It is getting quite annoying. I have to reboot the phone everytime this happens, and it still does not always solve the problem. I have also noticed battery life has gotten worse rather than better. In addition, there is more sluggishness moving through the apps. Please T-Mobile and Samsung issue a fix or at least allow a roll back until a fix is ready....
in addition to factory reset there is one other reset you can do to your phone which it to wipe the system cache. to do that, (with the phone on) pull the cover off the phone and pull the battery out. then put the battery back in, and press & hold volume up + volume down & press and hold the power button until you see the galaxy s 4g logo come up. then you can let go of all 3 buttons.
you'll see a menu come up that will look like:
- reboot system now
- wipe data / factory reset
- wipe cache partition
use the vol. up / down buttons to move the highlighted line to wipe cache partition and press the power button to select it (which will not hurt your phone: http://www.addictivetips.com/mobile/android-partitions-explained-boot-system-recovery-data-cache-misc/ but should help clear up any older cached files on your phone that doesn't get cleared when you do a factory reset).
then scroll to the reboot system and press the power button to select it to reboot back to the os and see if that has made things any better.
If that fails to solve your problem (I had a similar problem when I upgraded from froyo to gb), you may just try flashing the stock gingerbread image to your phone (if you do this you can brick your phone so be careful, these phones are hard to brick though, but nonetheless, proceed with caution, I'm not responsible.). it is essentially what you have on your phone now, except what happened during the upgrade left quite a bit of froyo files on your phone taking up quite a bit of already limited storage space on these phones. if you flash the stock gingerbread image (rather than the patched one that we all updated to) it actually ends up with the same thing but takes up less internal memory and I found it to be much more stable.
to load the tmobile gingerbread image you will loose all your data (like a factory default reset). you will need a USB cable attached to your computer and a driver from samgsung and the file from this website: http://forum.xda-developers.com/showthread.php?t=1358498
- to begin you download the first "Download Fully Back-To-Stock UVKJ6" file from the link above.
- then hook the USB cable to your computer
- remove the battery, sd card, and sim card from your phone (if you don't take your sd and sim out it may not work or may royally mess up your sim card & sd)
- press and hold Volume up + Volume down (don't touch your power button) while you insert the USB cable that is plugged into your computer
- this will bring up a screen on your phone that says press up to install an OS press down to continue to boot normally or something like that... you want to press up... This puts the phone into "Download mode" where you can "Flash" the stock gingerbread OS to it.
- Once your phone has the yeild sign on it, and you've downloaded the "Download Fully Back-To-Stock UVKJ6" file, you double click the "Download Fully Back-To-Stock UVKJ6" file and click the "Flash" button on the OneClick window (which is the app you downloaded). It will take you through pushing the sock gingerbread image back onto your phone (minus the froyo remenants that you now have) and should run quite a bit smoother once it comes back up.
- After it's done, it will reboot and do the voodoo lagfix bit where it talks to you, rebuilds the ext4 file system and all that... this takes a while so be patient.
- after that's done it may reboot again (its been a while since I did this, so I don't remember if it reboots again or not), but you should be good to go with a bit more stable of an OS and the same exact OS that you're currently running but with much less clutter and memory usage.