I've yet to find a solution to this problem, it isn't the solo mining by itself, it's something to do with the client etc. the problem is because people on this board don't see solo mining as profitable they aren't particularly helpful in giving any real answers about it so they just tend to rant about it instead so prepare yourself for them to spam this thread and not give you an answer lol
I'm sure if you stick around enough though someone will eventually respond.