Ok.basically, I fiddled around with the password and group options, i did not set any password but groups were created so now, when I open my file I am asked for the password....but I did not set any and leaving the field blank, I do not have access to the password section anymore in order to fix this!!!!

I know you'll probably think "what the hell did you need to do this.." but that's what we call discovering!!

Hope you can help!!

You cannot make groups without assigning them to passwords, so somewhere along the line you made a password too. It might be "<no password>" which means you just press return at the prompt.

Actually you can have Groups unassigned to any password. While "master" passwords belong to every Group, this is distinct from assigning passwords to a Group.

The <<no password>> option is a likely explanation here. However, older versions of FMP did have some password corruption issues that were fixed by v-revs.