I. Before You Begin
1. This is ONLY for GSM versions of the Galaxy Tab (uses a SIM card).
2. This is ONLY for devices that have been updated to firmware version JM* or KA* and in doing so got their bootloaders locked (they are unable to flash firmware).
IF YOU DO NOT HAVE A GSM GALAXY TAB OR YOU ARE NOT ON ONE OF THE ABOVE FIRMWARES, SKIP THIS PROCEDURE AND GO TO THE NEXT ONE:
II. Root Your Device.
1. Follow our How To Root Your Samsung Galaxy Tab procedure first, then come back to this procedure and continue.
III. Patch the Bootloader
1. Once you have root access, download the following apk file and save it to your computer.
Bootloader Patch (at the request of the developer of the app, this link now points to the XDA thread. You can download the apk from the bottom of the first post).
2. Plug in your tab via USB cable and mount the storage so we can transfer files to it.
3. Copy the apk file over to the root of your storage.
4. On your tab use a file explorer (Astro File Manager from the Market works well) and select the .apk file to begin installing it. Follow the prompts that come up to install it.
5. Once installed, open it and it will check to see if you even need the patch. If it says you do, it will allow you to click the Patch Bootloaders option. Select that and wait for it to finish.
IV. (Optional) Flash a ROM
1. You can now flash a custom recovery, ROM, etc. if you want by going to our How To Flash a Custom Recovery Image on the Galaxy Tab procedure.
Thanks to Chainfire and Rotohammer on XDA for this amazing patch!