Comma appears after the last taxonomy term in Safari and Chrome

The comma which separates taxonomy terms (tags) in node pages appears after the last term in Safari and Chrome.
Here is a screenshot: https://img.skitch.com/20110122-tur9fnmjyki113jt7nfmghttii.jpg

The relevant CSS code is:

.field-type-taxonomy-term-reference .field-item:after {
  content: ",";
}
.field-type-taxonomy-term-reference .field-item:last-child:after {
  content: normal;
}

I have found out, this is a WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=20032
A possible solution for this maybe using "" (empty string) instead of normal value.