CrackBerry Genius of Geniuses
I have been having this issue recently as well, since the night of the BIS update. I have 5 bars of service and am always on EDGE, yet my browser and BBM is slower than ever while everything else is working at their normal speed. My default browser works intermittenly. Sometimes the browser is messing up and I get the message "A communication error has occured" and when it does work, my BBM doesn't work properly. (I sent a BBM to a friend Thursday night, come Friday night it was still "sending".) My email is working fine, as well as all of my apps that require BIS connection. It is just my browser and BBM that are acting up.
At first I thought it was my OS but when I upgraded I still had the problem.
I ended up downgrading, then upgrading my OS, clearing my cache, call log, email inbox, text message inbox, and event log (yes, I know, not the brightest idea,) registered my Host Routing Table, resent my service books from BOTH my Blackberry and T-Mobile's BIS site, and did a battery pull after all of this was done. Nothing fixed the problem.
I've given up and am just dealing with it. I'm glad that the Curve has Wifi, otherwise I wouldn't be able to browse the web 95% of the time. If anyone can come up with a solution though, I would love to hear it.
(not trying to hijack your thread OP, just stating that I've been having the same problem as well.)