Maybe I’ve found a possible reason that cause that problem.
In Unity 4.x the dynamic font is available also on IOS and Android, so I’ve used this new functionality. But probably this doesn’t work so well on my project where I have many script with different GUI’s call.
Changing the font’s importing from dynamical to Unicode the problem seems to be solved. At least I hope
Sorry for digging this thread up.
I have the same issue when changing Unity 3.5.x to 4.2.x yesterday.
Have anybody can fix this bug? Or we need to wait next release?