[Q] Will flashing non-CM ROM repartition back to standard layout?

[topshot]

I need to run Mobile Odin Lite to return to stock (bad USB port so this is my only option AFAIK), but it won't run because I have CM loaded (phone came that way) so it gives an error that the partitions aren't correct. Will flashing a non-CM ROM repartition the phone back to a "standard" partition layout so Mobile Odin will then run?

I get wifi but no mobile signal at all with CM 7.1, 9 beta and 9.1. IMEIs match, phone is unlocked and baseband is listed as I9000UGKG3. I'm hoping there's something messed up in software rather than hardware.

Edit: Mods - you can delete this.