UPDATE: 1st June 2007
I’m still having bouncy wi-fi problems, despite running the WinsockXPFi app once more.

Stop reading, start speaking
Stop translating in your head and start speaking Italian for real with the only audio course that prompt you to speak.
I seem to have cured my bouncy wi-fi problem. Often, when there were other wi-fi connections active, both secure and non-secure in my area, my wi-fi connection to the www would come on and go off all the time. This was annoying to say the least. I tried updating the wi-fi drivers, reseting the access point and even installing a wi-fi trouble shooting application. All to no avail. Until now.
After hunting around the Internet I discovered this little application: WinsockXPFix. You don’t have to install it, just click on it, back up your registry, either using this program or something else and ask it to repair. Re-start your PC as instructed and you should experience wi-fi stability. I have for two days so far. So, if you have bouncy wi-fi and have Windows XP, Home or Pro, give it a go.
It seems as though installing or removing certain programs can corrupt a section of Windows which leaves your system with erroneous Window’s registry settings. This little app puts things back as they should be and seems to restore wi-fi stability.