Splitting Work Areas and other problems

Ok first question: How do I split areas in blender 2.5?!! The method I used in 2.4 does not work, ie no more clicking the divider with my middle mouse button.

Second how do I reset my blender 2.5 to default, or get into the preferences to set them in the first place?

Third I think I accidently deleted the copisiting mode, y’know ctrl left arrow, well it only cycles through 1-5, I’m guessing compostng would be on 6.

And is there a reason when I put the 3D view in the lower work area that it doesn’t render properly? I mean in the top 3D view everything s fine and normal, but in the bottom one everythng is flat… So yeah not normal and how do I fix it?

To split / join windows see here http://www.blenderguru.com/whered-that-button-go/
To reset blender use the File / Load Factory Defaults. Make any changes tyou want then Ctrl+U to save as startup default.
Preferences are at File / User Prefernces