AVGA some games don't work?

[Xtro]

Hi, I updated to latest GameEx 9.12 after rebuilding my MAME romset to v.123. I noticed that the screensaver didn't work, the rom loaded and then inmediatly returned to GameEx frontend. The log says everything is OK (only shows that game plays for couple ms). I tried to run several games that did the same, while others run perfectly. For example Commando (World) doesn't run from GameEx, but if I run it from the commandline it works perfect, so is not a problem with the MAME config or the AVGAres tool (I am using an ArcadeVGA card). I have rebuild the mame list from GameEx, run another time AVGAres, erased the arguments in MAME commandline, and even used another MAME... I don't know what more to try. I think is a specific problem with MAME, the console emulators seem OK, and the blank screensaver works, but some MAME games work and others no. I am not 100% sure but I think that most games that don't work are vertical ones, horizontals seem ok, but I haven't tried everyone. What more should I try?

Thanks in advance

EDIT: In fact the problem was only with vertical games. I solved activating the ArcadeVGA mode, but this way it stretches some games looking less original than with mame directly. The good is that it keeps the correct aspect ratio. Has someone configured properly MAME set 123 with ArcadeVGA?