I'm getting a really weird and really dangerous error in Dreamweaver CS3.

I cannot replicate it, it happens randomly:

It happens when I am making a lot of small edits to a CSS file and then previewing the HTML file in the browser. After about 15-20 save+previews, Dreamweaver will tell me "access is denied" when I go to save my CSS file. If I try to CTRL+S again, it pops up a Save As dialogue box. If I try to save the CSS file with its existing name, it tells me I don't have permission - then it deletes the file completely!

However, if I save the CSS file with a different name, there's no problem. But I do have to go into the HTML page and re-link the stylesheet.

I have no idea what could be causing this, but Dreamweaver already ate one of my CSS files that I worked hours on