Try use byte. GPU can have problems with read/write which are not aligned at least to 4 bytes.
This 32bit align was it, thx!
I've tried byte, and byte too: they'r bad also.
Only byte and GL_INT_10_10_10_2 worked perfectly.
So from now I'll mix the vertex data with the normals, and compress them onto short. Hope that will do fine on any kind of hardware.