Unusual SM Problem...

[biohazard71]

This problem started happening a couple months after I got SM4...what happens is after every 2 or 3 songs I play, after I hit enter on the results screen, it goes to the loading screen and just sits there for a good minute or two, after which it goes back to song selection.
The same problem happens when I try to go from the song selection to the main menu after I play at least one song. I hit escape (or sometimes ScrollLock) and it just sits there for litterally 45 or so seconds before actually taking me where I want to go. It always takes 9 or so minutes just to play 3-4 songs, which really get on the nerves after awhile.
This problem has gone on for a while...uninstalling & reinstalling does nothing, and virus scanners show non-infected files. My computer is more than capable of running it on high settings, and turning them to lower or the lowest setting doesn't make a difference. Is there any way to get rid of this or fix it somehow?

Thanks in advance.