Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.599
diff -u -F^f -r1.599 common.inc
--- includes/common.inc	11 Dec 2006 17:47:36 -0000	1.599
+++ includes/common.inc	11 Dec 2006 20:52:36 -0000
@@ -1503,9 +1503,9 @@ function drupal_build_css_cache($types, 
 
     // Perform some safe CSS optimizations.
     $data = preg_replace('<
-      \s*([@{}:;\)])\s* |          # Remove whitespace around separators.
-      /\*([^*\\\\]|\*(?!/))+\*/ |  # Remove comments that are not CSS hacks.
-      [\n\r]                       # Remove line breaks.
+      \s*([@{}:;,]|\)\s|\s\()\s* |  # Remove whitespace around separators, but keep space around parentheses.
+      /\*([^*\\\\]|\*(?!/))+\*/ |   # Remove comments that are not CSS hacks.
+      [\n\r]                        # Remove line breaks.
       >x', '\1', $data);
 
     // Create the CSS file.