So this is the steps Im going to try as SOON as somebody generous can upload the extracted UK cabs:
Complete R3A Generic_UK Cab pack : http://www.megaupload.com/?d=35LZ05OO thanks to rx.
NOTE: BEFORE you do ANY of the steps below, make sure to DELETE C:\Program Files\Sony Ericsson\Update Service\db from my computer or you won't get MR2!
1) Do clean install of WM 6.5.2 using the soft-reset during SE customization bootscreen OR just simply clear phone memory located in settings -> system -> clear phone memory.
1º Open SEUS, start a new update. EVEN IF IT SAYS YOU HAVE LATEST VERS, UPDATE IT ANYWAY.
2º ONCE IT REBOOTS, CALIBRATION SCREEN APPEARS. RIGHT AFTER CLICKING ON THE CROSSES, IT WILL APPEAR THE SONY ERICSSON LOGO, AND IT WILL START APPLYING THE CABS. PUSH THE RESET RIGHT after it starts applying (hidden behind the stilus, opening the battery cover).
3º After rebooting, the Sony Logo will appear again asking to retry. Press NO.
Credits to dreamcrawler
4) Install ALL cabs to device, soft reset.
5) Update on SEUS, it will say latest firmware already, say YES to install anyway
6) Grats on Generic_UK and hello to MR2 =)
Comments: I AM NOW AN EXTREMELY PROUD OWNER OF THE X2 NOW! NO REGRETS, GOOD JOB SE, THIS IS THE WAY THE X2 SHOULD HAVE BEEN WHEN IT WAS FIRST RELEASED! =)