If you haven't tried it already, you can check out the CSS validator at
CSS Validator. It does give a bit more information about errors in stylesheets including some proprietary items.
Sample output:
Code:
1 Unrecognized at-rule @namespace h
22 .epbody Value Error : height only 0 can be a length. You must put a unit after your number : 792
23 .epbody Value Error : width only 0 can be a length. You must put a unit after your number : 528
41 .paraindent Value Error : orphans 0 is not valid, only values greater than 0 allowed. : 0
42 .paraindent Property so-language doesn't exist : en-US
61 .paranonindent Value Error : widows 0 is not valid, only values greater than 0 allowed. : 0