Well BF3 will get fps drops now and then especially on MP... a lot of it depends on res and settings though....
Just to double check, is your monitor capable of displaying more than 60fps?, ie more than 60hz refresh rate?
No, I have 2 Acer 20" S200HL monitors and the refresh rate is 60hz. Its weird because I've never had it do that before. But it could have been that I was playing on 32 player Gun Master servers when I noticed it.