Ethernet/Wireless internet problems..This is Driving me CRAZY..please help!

Question

Alright i hope someone out there can solve my problem because i am about to throw my macbook against the wall. This is my problem:
Everytime i go on to the internet, in order for the internet to work i have to pull my ethernet cable out of the plug, plug it back in and refresh the page. The internet then works for about 4 pages on avg. and then it times out and says im not connected. In order to continue surfing on the net i have to pull the cable out and plug it back in. The wireless acts the same way. It will work and then times out. I have to turn off the airport and back on to get any internet.
The browsers im using are Safari 3.1.2 and Firefox 3.0.1 and both act the same way. My roommate has a PC and has had no problems whatsoever. Our internet comes through the wall from a plug not from a router. I personally believe that it is my computer because i have tried getting internet from the plug in his room and the same thing happens. The wireless around my school comes from different towers and no matter where im at the same thing happens. I dont believe that its the internet. Ohh and one more piece of info. My first year at school my computer gave me NO internet problems whatsoever. I bought the computer brand new in June of 2007.
If anyone knows how to fix this extremely annoying problem, please help me!! Thanks to all who answer~

Answer 1

Hi
I'm getting a problem which may be related, and i've figured out some workarounds (sort of inadequate ones but at least they're something).
PROBLEM DESCRIPTION: almost immediately after installing the 10.5.5. system update, my MacBook started disconnecting itself from my wireless network. i'd be working online and suddenly i'd notice that only 3 bars of the AirPort icon on the menu bar would be showing and that the internet connection was no longer there. the only way to get the connection back would be to switch airport off and then back on and it would connect again. a couple of minutes later the connection would be gone again. infuriating stuff! i checked the system log using the Apple System Profiler (from the Apple menu) and found some messages about there being too many state changes detected on the AirPort network interface and that measures were being taken to fix stuff. it's a pity i didn't save the original error message since i no longer get it, but here's one I found that's identical reported by someone else:
May 25 16:50:57 phoebe mDNSResponder[22]: Note: Frequent transitions for interface en1
(FE80:0000:0000:0000:021E:C2FF:FEB9:8B73); network traffic reduction measures in effect
anyway, the "measures" seemed to be to simply disconnect me from the net, which wasn't great. now the forums mentioned various solutions, but none of them actually worked.
SOLUTION/WORKAROUND: two things seem to have made a difference. 1. i downloaded the combo 10.5.5. system updater and reinstalled it. somehow after i did this the problem would no longer happen (at least those errors would no longer occur). 2. keeping my ipod touch wireless interface switched off, because whenever my touch comes online within a minute or two the iBook disconnects from the net.
COMMENTS: (1) even now if i connect to the wireless network with my iPod, my MacBook's connection will drop - so my solution is to not connect to the wireless network with my iPod touch, which ***** because i like to read stuff in bed on the touch sometimes. (2) reinstalling the system update (the combo version) definitely helped, because before i kept getting that error message in the system log, and even if the iPod touch was switched off the MacBook would still disconnect. (3) this suggest that there were two separate problems, one to do with a corrupted AirPort driver or something of that sort (which was fixed when I reinstalled the system update), and another to do with being kicked off when the iPod touch connects to the wireless network (this problem remains).
I've replace my Linksys wireless router with a Netgear wireless router, but that's made no difference, so i'm pretty sure that the problem has to do with the MacBook - either the hardware or the software. I plan to get another hard disk soon at which point i'll do a clear reinstall of the OS, and if the problem persists then i'll know that it's a MacBook hardware problem. =(
i'll post again here in the future, but if anyone has comments or suggestions or reports of this kind of problem then your input would be highly appreciated.
thanx
dr.colekat