It's the case issue
Clear your cookies so you can log into the blog first as mrspenguin and allow your browser to remember your login. The blog login is case sensitive and won't allow upper case letters.
The forum login is only case sensitive for the password, not the username. So you can set your cookie to remember mrspenguin and you'll still be able to log in as long as your password is correct.
If you have any problems, send me a PM. There's another option we can try.