I have just built a new computer using the Coolermaster storm enforcer case. I really like the case but have one problem with it. The top of the case has an open mesh where you can fit an optional fan. It has no default cover or dust filter so the all the important components of the computer are directly open to dust. This seems like a pretty big oversight by Coolermaster to me or is dust not that big a problem? Do the fans in the case keep the dust from being a problem? Should I cover the mesh holes or will this prevent proper cooling of case?