Getting random 500 errors on the MVC and ASP websites on iis7

It seems to happen on almost every site and does not matter if it is an ASP or .NET website. if you refresh right after you get that error it goes away and won't come back by just hitting refresh a bunch of times. I have two servers working with load balancing for IIS. EDIT Also these are valid paths for folder names. The pages connect to a Microsoft SQL databse on aother server. Application pools are setup to use a different domain user for all of the A websites as well as for every other letter of the alphabet as instructed by microsoft. Each website has its own application pool. EDIT