I am having problems getting roms to work with gngeo2x (tested with 0.6.11 and 0.6.12). Some roms worked immediately without problems (mslug1, mslug2, mslugx, samsho5) but others didn't.
I do have the neogeo bios and also the uni-bios.rom v2.2. The roms do work on the PC using NeoRageX 0.8c but...