Check your regexes. The webkit-only tags used are

-webkit-appearance -webkit-appearence [sic] -webkit-background-clip -webkit-border-image -webkit-border-radius -webkit-box-reflect -webkit-box-shadow -webkit-box-sizing -webkit-gradient -webkit-mask-box-image -webkit-resizer -webkit-scrollbar -webkit-tap-highlight-color -webkit-track-piece -webkit-transform -webkit-transition -webkit-user-select

Many of them will be in the final CSS3 spec, e.g. box-shadow and border-radius.

Great work pushing HTML5 and CSS3.