I've figured it out.
I was trying to compile a module with 1.99 MB!!!
Not a good idea...
So I've made separated modules, and the problem was gone.
Also, I had a memory problem - solved changing the value in the B4A ini file: MaxRamForDex=1536
And... had some freezing problems also, because I declared an array as Dim nArray(0 to 2) instead of Dim nArray(3) - only troubles...