cdata - if IE 7 statement

I am trying to embed an if statement around some xsl (see attached)
I have the IE 6 condition coming through without any problems but rhythmyx is stripping out the iIE 7 condition when it publishes!!

Any ideas on a fix for this?

The key difference I see is that the IE7 stuff is wrapped in an xsl:comment and the IE6 stuff is wrapped in xsl:text. I think comments get stripped by the server’s processing. Does it behave the same way in preview?