Buy App button not working iTunes 10.6 Windows 7 (used to work)

Question

Hello Community - color me stumped beyond compare...
I can no longer make purchases of apps (free or otherwise) using my Apple ID on iTunes 10.6.1.7 on Windows 7.  It used to work as of Tue 10/2/2013 around 8pm. Later that evening it stopped working and hasn't allowed a purchase since.  Clicking on FREE APP button or {PRICE} BUY APP button, visually makes the appearance that the button is clicked but doesn't do anything after that.
If I'm logged in to iTunes using my account - it visually makes the appearance that it the purchase button is clicked and does nothing.  If I'm logged out, it visually makes the appearance that it is clicked and it doesn't ask for me to log in like it used to.
I've tried several solutions, all of them fails.  I've conducted closed experiments, and still cannot isolate the solution.
Not wanting to go to iTunes 11, I upgraded to 10.6.3 (64x version) iTunes for Windows 7, and got the same non-responsive results.
I've had someone try to download on their system (they were using iTunes 11 on their PC) and it downloadeds using my Apple ID account.
I've rolled my PC's Win 7 system settings to a previous day when it was working, and it's still not working back to iTunes 10.6.1.7.
I've check iTunes diagnostics / firewall settings and although the iTunes diagnosis says: "Windows Firewall is on." AND it says "iTunes is NOT enabled in Windows Firewall." this is not accurate as iTunes is showing firewall enabled in Windows. (see image)
I've reset my modem/router (which is wired to this PC)... still no downloads.
I'm just stumped - anyone else experiencing similar issues or has anothe idea for solution?
I've ask for Apple's help but have not heard anything in 24+ hours, so I'm reaching out to the community.
Thanks in advance!
PS: The downloads have also stopped on an older laptop using my ID on an older iTunes using wireless to the same modem/router whereas downloads used to work on that laptop.

Answer 1

UPDATE: Welp - my solution was downloading iTunes 11; it restored the ability to purchase items.  On the minus side I already miss coverflow, but on the plus side my appnabbing hobby is back on track... 240 downloads later.  Missed out on 20 travel apps and a smattering of some others that went free and went back to sale price during the 2+ day "outage", but that's alright - they'll be back to free in another 2 years.
The rest of iTunes 11 is not as bad as I thought; it will take some time getting used to it.  You might miss coverflow display view as you only get TILES view or LIST view to choose from.  Also, within the Apps Library it does not give you a count of the number of highlighted apps like iTunes 10 did.  I'm sure that was an oversight in design - likely to comeback in another version.
Although you can no longer double-click a category to create break-out windows as iTunes 10 allowed, I was happy to see you can get a separate download window if you click the DOWN ARROW next to search field while something is downloading.  That's a plus.
Apple Support has only reached out once during the 2+ days to suggest logging out of iTunes, close the program, and re-launch / login and try to download again. (by the way, that did not work).  If I waited one day apiece to try out seven different trouble-shoots one at a time, I'd be a week into trouble-shooting with no solution in sight.
If you are fearful as I was of iTunes 11, don't be.  It works... just not like how you remember.  Plus you can always go back and get a previous version of iTunes for PC - just Google keywords: "archived versions of itunes pc" (without quotes).  The first hit is comprehensive.  The site used to have MAC archived versions, but no more; I have not tried searching for Mac archive.
Cheers!