For those of you who are using Dreamweaver on a daily basis, you may have  run into this problem.   You try to open a file in Dreamweaver from a site you have been working on and Dreamweaver mysteriously locks up.    Weird, huh???   Apparently,  Dreamweaver crashes in Windows if you make an edit to a CSS file that changes the size of the file to exactly 8191 bytes or an increment of 8191 bytes. In addition, Dreamweaver won’t restart unless you change the size of the CSS file.

http://blog.zoblue.com/2008/04/06/dreamweaver-cs3-and-css-file-size