Arduino software won't start

Hi, I’m having a lot of trouble with the Arduino software. When I open it, it only has the “Arduino” menu and the Apple logo in the upper left corner, but it has no upper menu bar (with File, Edit, Sketch, Tools, etc.) and as a result, I can’t open, create, or upload sketches. I can still use the Preferences pane and everything under the “Arduino” menu. I’m using Mac OS X 10.6.8 and Arduino 1.0 on a MacBook. I would really like to know what is going on here. Thanks in advance!

Sorry about accidental double posting!

No problem on double post, I deleted the duplicate.
I'm not a Mac user tho ...

Arduino 1.0 on a MacBook.

1.0 or 1.0.5?

Sorry, I think I downloaded the Windows software by mistake. It works now.