TMo has released 188.8.131.52 for the 8100 Pearl.
This OS will work on any Pearl, regardless of carrier.
Pkg v184.108.40.206 app v220.127.116.11 Plt v18.104.22.168
File name: 8100M_PBr4.2.1_rel168_PL22.214.171.124_A126.96.36.199.exe
Download the OS here
Instructions for loading this OS on ANY carrier's 8100:
Instructions for installing:
(Be sure to check out TMo's installation instructions at the download site.)
1. Make sure you have the latest version of Desktop Manager installed. It's 4.2 SP2. Download it here
or from the TMobile site at the link above.
2. Download the above file to the PC then install it to the PC by running the file you downloaded.
3. Locate the vendor.xml file and delete it. It's located in c:\program files\common files\research in motion\apploader
4. Plug in BB and Open Desktop Manager. You should be prompted to upgrade.
The process takes about 45 minutes to an hour depending on how much data you have to backup and restore during the process. Once it's done loading the new OS it will reboot (it may do this twice during the entire process.) You will see a white screen with an hourglass for up to 20 minutes at a time while the DM says "waiting for initialization." Don't unplug from the PC & Don't remove the battery unless the spinning hourglass has been there for 30 minutes or more. If the hourglass has been spinning for more than 30 minutes continuously you will need to wipe the device with JL_Cmder (close out of Desktop Manager during this process.) You will then end up with a white screen with small icons and an error code number like 507 or 543.
If you end up with a white screen with small icons and the number 507/543 (which happens occasionally during an upgrade process,) simply connect to DM again and run application loader again and it should load the OS to the device. You will lose your 3rd party apps if this happens. You can prevent this if you have a current 3rd party app "backup." Learn how to backup 3rd party apps here
Edited Blackberry.alx and LBS.alx's can be found here
(link to previous OS sticky thread click here