Using the native browser, it seems to be locking up recently. If I open some links it may try forever. But if I kill the task and restart, it works fine.
You might try to clear the browser's data. Go to Menu, then System Settings (ICS), or Settings (Gingerbread), then Apps, then All, then Browser. From there, select Clear Data.
I've noticed that a lot lately except mine is in other programs as well I did notice the arrows my 3g are not blinking or solid when it happens to me. I feel like I Have my thunderbolt again, I have to place it in airplane mode and take it out of airplane to get data back on quite a few occasions lately.