CS5 to CS5.5

Hi All,

I'm just wondering would there be any problem if i move to CS5 to CS5.5?

If i open CS5 files in CS5.5 it'll say ______[converted] but will it be any problem?? -----> and if i save a cs5 file to cs5.5 file that's gonna be another problem??

and also what is really the different between cs5 and cs5.5 ??

thank you!