restrictions for RMAP formatted maps?

i converted all my maps to RMAP format using compegps, to be used on orux.

i can open them now with other RMAP compatible applications without any problems, but...

unfortunately, ORUX is only able to open some of them. i.e. some work without any problems, while others generate an error message in ORUX.

what are the restrictions for RMAPs to be loaded into ORUX???

are there restrictions in file size, projection,...???

thanx!