Valve Cover won't come off

I'm working on a valve cover gasket replacement. It's leaking oil, so I know that's one oil leak I can finally plug. However.... all sixteen T40 bolts are out, I've banged around on the thing with a rubber mallet and even took a regular hammer to it a bit more lightly, and it's just not comin' off. I can't get a screwdriver in anywhere to try to pry, and I'm not sure what else to do. Any suggestions?

I can grab some pictures in an hour if someone thinks they'll be of any help.