I test with this maps:
[Only registered and activated users can see links. ]
using "add zeros" method to compensate the changes in offset (it is faster to do as i have to do it manually)
I only convert on tile, not all of them, and it worked!!
When converting from pseudo-nt to non-nt i got a "non-nt locked map", as the maps seems to be locked.
Then i used [Only registered and activated users can see links. ] to unlock it and...
I Can open it with gpsmapedit, cgpsmapper etc...