Syntax table issues

I'm working this week and next on improving the recent (or not-so-recent) syntax table changes in an effort to get them ready for a 21.4 release. I've heard for awhile that the syntax table performance in XEmacs has been lacking since the patch was applied, but I haven't been able to get enough details to actually track down the problem. If anyone can give me any information on a _reproducible_ case (preferably with -vanilla enabled) that illustrates bugs or poor performance with the syntax table code, I'd appreciate it tremendously. Thanks very much for your time and patience.