We’d been experienceing errors with many feed links during the past 3 months. Today we upgraded php on the server and updated installs of Sablotron (version 1.0.3) and domxml which appears to have corrected multiple errors we’d been experiencing with XSLT functions on the user page outputs.

For those involved in this kind of work here are some links…
XSLT Functions
Sablotron

Some examples of user pages with xslt ad supported output…
SexyPhotos
San-Diego-Local
Ozzfest
HandBags
Nylons-Photo-Feed
WordCamp2007
WordPress
online-coupon-codes

Thanks to Sergey and Tommy for getting these features back up and running smoothly.