[1.1.0] Cannot modify project size

Debian Squeeze 1.1.0 from deb.
Once you have defined your project, it is impossible to modify its properties.
Went to see the OSP file, but can't find out where is what I want.
In this case, still working on my project of making a video from shots taken during a concert.
I estimated the total length to 30 minutes. well it isn't. it's more.
Ok, I could do it, do the rest in a separate project and merge the two, but having access tot he properties of the project would make more sense, even if you need to grey out some attributes for whatever reason.
making a 30 min project go up to 40 should not be a problem.