T-mobile Tech support knows less than a regular costumer...so helpless...I had the same problem..
make sure you back up all your apps (specially the ones you downloaded) and the apps data (such as if you have call filter back it up..) most of apps and data on this phone is stored on your card but to be safe I will do it at least to the ones you care not to loose info
below is what T-mobile couldn't help me with until my phone froze completely...hope it helps
Android 2.2 System Update for T-Mobile myTouch 3G Slide | 04.04.2011
HTC and T-Mobile are proud to launch a system upgrade for the myTouch 3G Slide. This update will bring the following enhancements to the device:
• Android 2.2.1 FroYo
• Wi-Fi calling
• Wi-Fi hotspot
• USB Tethering (Internet Sharing)
• Low storage (User Data) notification mechanism
• Resolves issues with text and picture messaging
• Resolves some Bluetooth compatibility issues
• Improves compatibility with new Bluetooth devices
• Improves stability and reliability of the device
• Other various minor bug fixes more
here is the link to the update
http://www.htc.com/us/Content/Documents/HTC_myTouch3G_slide/T-Mobile_myTouch_3G_Slide_Software_Update_2.15.531.3.htmlor here is the page where I got the info if you feel safer
http://www.htc.com/us/support/t-mobile-mytouch-3g-slide/downloads/
