AIS Thailand released an Official OS Update for the BB Curve 3G 9300 version 188.8.131.522. This is an official release but you may need to delete the vendor file.
To download this file follow this link.
Note: This OS will not install on any other BlackBerry besides the one mentioned above and is an official release. If you do not know how to upgrade your BlackBerry OS please start by reading this step by step guide.Don’t forget to delete the vendor.xml file located in c:program files>common files>research in motion>apploader to install it on a different carriers device. Don’t forget our usual warnings: do not download and install these updates if you don’t know what you’re doing. Incorrect procedure or just bad luck could render your BlackBerry inoperative or unstable.