Hum... my project is not really big, it just contain a fun quantity of files (48 small files (the bigger one have 150 lines) should have been affected by the change, and I just notice 15 which should be in that workspace and can not have been affected. They are not mine and are not using the same license so...) and libs.
In fact, I did not had that problem on a project, but on a workspace. I guess C::B sources would be big enough to have that problem.
Or maybe my computer is a weak one, I also forgot to say that is is a simple netbook (2x1.55gHz).
But I don't think that's a reason, I never had such kind of problems before this week... (But I did not request a change on 48 files, too)