Originally Posted by John Clark
Yes. But unless you have other problems aside from the theme/slowdown issue there is no need to reload the OS. Simply remove the theme and reboot. I believe that fixes your issue.
Install Desktop Manager (if it's not already.)
Download 188.8.131.52 OS to your PC and install to the PC.
Delete the vendor.xml file located in c:\program files\common files\research in motion\apploader.
Backup your device using Desktop Manager.
Then use JL_Cmder (in my signature) to wipe the handheld. Make sure Desktop Manager is not running while you use JL_Cmder. When the wipe is complete the handheld will display a 507 error. Close JL_Cmder.
Run Desktop Manager, select USB from the Connection menu and then run Application Loader and it will reinstall your OS.
Thank you! I will try removing the themes first though.
Reloading OS is just a back up plan, but it's just good to know the way you know.