how to go back to 900/1800 (which rom?)

[Gonzo]

After upgrading to t-mobile rom gsm module was working until I hit the "band" tab from phone menu. of course what happened I realized after reading posts from forum.
Now, I need help how to go back to 900/1800 frequency (Poland) - which rom to use, where to download it or how to change to these frequencies.
help pls.

[ultimize]

for 900/1800 use v. 4.00.01, 4.00.05 , 4.00.11 for upgrade to WM2003

(v.4.01 & 4.05 you can up/downgrade by program setup)

[engine_lfc]

you can switch it on the bootloader !!!