Try a battery pull and see if it gets a little better. After that, you can update your PRL by dialing *228 and select option 2.
I apologize for grave-digging an old thread, but I'm having the same issue as the OP with my BB Storm 9530. The problem occurs mainly when I tether it but the BB browser has also been incredibly slow the past 2 months. I've talked to technical support and they had me reinstall VZAM and that increased the speed on my computer a little (it went from an average of 14kbps to about 30 for a short amount of time before the disconnects or hang ups) and more often than not, a website won't even load on both my PC and on my phone.
For informational purposes, the websites I mainly visit are google, wiki, hotmail, CNN. I haven't tried any heavy duty stuff through the tether. Technical support wanted me to call back if I was still having the same issue as the OP but I figured I'd see if anyone here has been having the same problem and what they did to correct it. I've done battery pulls, *228 updates, registering my phone on a routing network, updating all of my software (for both PC and my phone). I'm thinking it just may be an issue with my Storm (which would actually be the first issue I've ever had with it since I bought it over a year ago) and that I may need to replace it.
So my question is this: Is there anything else I can do? Any tricks you guys have done or heard of to fix this problem before I call tech support again? Like I said, the battery pulls will fix the issue for a short amount of time before it happens again and it gets a bit annoying to have to do it every few minutes just to access my data services.