preg_match() error?

ok, i upgraded to 2.06 from 2.05 just as the doctor ordered and am now running into quite a bit of problems. this is the error that i get:

Warning: preg_match(): Compilation failed: nothing to repeat at offset 1 in E:\Domains\tery.com\wwwroot\journal\wp-includes\classes.php on line 1554

my guess is that either
a – it’s a php error in the classes.php document, so the script needs to be debugged
b – there’s a db error, so i need to edit the tables somewhere
c – there’s a plugin conflict, so i need to go down that rabbit hole

ok, lemme set the stage
– server host is iis, not apache
– supports mysql4, php, all that pre-requisite good stuff
– v 2.05 was working out perfectly fine until i upgraded, changed the wordpress directory from “wordpress” to “journal” (don’t worry, i changed the url string in options)

plugins installed:
– akismet.php
– batch-categories.php
– blogger-image-import.php
– category-tagging.php
– customizable-post-listings.phps
– deans_permalinks_migration.php
– encodedpermalinks.php
– fixdb.php
– jeromes-keywords.php
– jpf_calendar.php
– mms2wp.php
– preview_theme.php
– sem-admin.php
– underscorepermalinks.php
– validate-php.php
– wp-admin-tiger.php
– wp-db-backup.php
– wp-phpmyadmin.php
– ylsy_permalink_redirect.php

any help would be GRATEFULLY appreciated since my blog is now down until i get this issue sorted out