Does changing the ROM effect the SIMlock?

[Flavio]

I have bought a SIMlockfree O2 XDAIIs. I want to upgrade the ROM to a non O2 ROM (KPN). Would this effect the SIMlock status?
If I go back to the original O2 ROM in case the ROM upgrade fails would this also effect the SIMlock status?

[cruisin-thru]

The simlock is not affected by rom change.