Cannot connect to https or encrypted sites (banks, pay-sites etc)

Question

Since two weeks I can no longer connect to most https sites.
Some are very slow but finally show up after a minute or two (like finance.yahoo.com). One bank site (Interactive Brokers) allows me in, albeit very slowly but then they are only half functional.  Some payment sites appear unformatted.   Others just hang like my bank site.  I get into Apple Support https site but then it hangs when I sign in.  Looks like a timeout issue.  Some sites have more patience and I can go further in, others not.
This happened on my 17" MacBook Pro 8,3 with Lion (it is Raided onto two SSD drives, the second having replaced my DVD). The whole system worked flawlessly for about a year.    I upgraded to Mountain Lion hoping this might reset things as before.
This happens with Safari, Chrome or Firefox and also with Internet Explorer from a VirtualMachine with WMware, on the same MPB 17 machine.
This happens with my wireless router as well as with a wireless SimCard using a different provider.
I did the usual tricks of clearing caches etc, resetting Safari and the others both before and after upgrading to MLion.  I had no Firewall on or Parental controls.
I tried to make a new location network, and I tried to change the MTU to a different value.  All to no avail.
THIS DOES NOT happen on two other machines in the office: a Mac PRO  and on a MacBook AIR 10.6.7 and Safari 5.0.4 which briskily open all those sites.
Thus I conclude that it may not the browsers, as they all do not work on the MBP but work on the other machines;  it is not the wireless networks as both do not work with the MBP but they do work with the other machines.  Likewise for the ISPs.
It started right after my bank had a major down time after putting up a new site and software, so I initially thought it was their fault.  And since then it started affecting also the other sites.  Thus I thought it may be a bug within the system, but I have now finished all my ammunitions and now need help.
I noticed that similar problems happened before in this community, as I have seen posts dating a while back and some were resolved with various tricks which have not solved my problem.
Anybody with a suggestion?  Thanks
gp
PS I should add that everything else seem to work ok, except that in one of my datafeeds where I place orders (trading platform) there seems to be a marked delay 2-3 seconds whereby these orders were instantaneous before..)

Answer 1

Please read this whole message before doing anything.
This procedure is a diagnostic test. It won’t solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.
Third-party system modifications are a common cause of usability problems. By a “system modification,” I mean software that affects the operation of other software — potentially for the worse. The following procedure will help identify which such modifications you've installed. Don’t be alarmed by the complexity of these instructions — they’re easy to carry out and won’t change anything on your Mac. 
These steps are to be taken while booted in “normal” mode, not in safe mode. If you’re now running in safe mode, reboot as usual before continuing. 
Below are instructions to enter some UNIX shell commands. The commands are harmless, but they must be entered exactly as given in order to work. If you have doubts about the safety of the procedure suggested here, search this site for other discussions in which it’s been followed without any report of ill effects. 
Some of the commands will line-wrap or scroll in your browser, but each one is really just a single line, all of which must be selected. You can accomplish this easily by triple-clicking anywhere in the line. The whole line will highlight, and you can then either copy or drag it. The headings “Step 1” and so on are not part of the commands. 
Note: If you have more than one user account, Step 2 must be taken as an administrator. Ordinarily that would be the user created automatically when you booted the system for the first time. The other steps should be taken as the user who has the problem, if different. Most personal Macs have only one user, and in that case this paragraph doesn’t apply. 
Launch the Terminal application in any of the following ways: 
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.) 
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens. 
☞ Open LaunchPad. Click Utilities, then Terminal in the page that opens. 
When you launch Terminal, a text window will open with a line already in it, ending either in a dollar sign (“$”) or a percent sign (“%”). If you get the percent sign, enter “sh” and press return. You should then get a new line ending in a dollar sign. 
Step 1 
Copy or drag — do not type — the line below into the Terminal window, then press return:
kextstat -kl | awk '!/com\.apple/{printf "%s %s\n", $6, $7}' 
Post the lines of output (if any) that appear below what you just entered (the text, please, not a screenshot.) You can omit the final line ending in “$”. 
Step 2 
Repeat with this line:
sudo launchctl list | sed 1d | awk '!/0x|com\.(apple|openssh|vix)|edu\.mit|org\.(amavis|apache|cups|isc|ntp|postfix|x)/{print $3}' 
This time, you'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning not to screw up. You don't need to post the warning. 
Note: If you don’t have a login password, you’ll need to set one before taking this step. If that’s not possible, skip to the next step. 
Step 3
launchctl list | sed 1d | awk '!/0x|com\.apple|edu\.mit|org\.(x|openbsd)/{print $3}' 
Step 4
ls -1A /e*/mach* {,/}L*/{Ad,Compon,Ex,Fram,In,Keyb,La,Mail/Bu,P*P,Priv,Qu,Scripti,Servi,Spo,Sta}* L*/Fonts 2> /dev/null  
Important: If you formerly synchronized with a MobileMe account, your me.com email address may appear in the output of the above command. If so, anonymize it before posting. 
Step 5
osascript -e 'tell application "System Events" to get name of every login item' 2> /dev/null 
Remember, steps 1-5 are all drag-and-drop or copy-and-paste, whichever you prefer — no typing, except your password. Also remember to post the output. 
You can then quit Terminal.