Here are the errors I get from http://jigsaw.w3.org/css-validator

URI : http://MYSITE.net/sites/all/themes/engines/zengine/css/zengine.css
40 	blockquote 	Value Error : border Too many values or values are not recognized : 1px 0 #ccc solid
URI : http://MYSITE.net/sites/all/themes/zen_basic/css/fonts.css
12 	body 	Parse Error *font-size:small;
13 	body 	Parse error - Unrecognized *font:x-small;
14 	body 	Parse error - Unrecognized }
26 	pre, code 	Parse Error *font-size:100%;
30 	pre, code 	Parse error - Unrecognized }
53 	h1.title 	Parse Error .node .submitted { font-size: 95%; }

Posting here in case anyone else has run into this...
:) Scott