Q: I get this error: "preg_match() [function.preg-match]: Compilation failed: unrecognized character after (? at offset XX"
A: Ask your web host to upgrade their version of PCRE. Any version released since 2006 should do.
Q: Is this compatible with XenForo 2.0?
A: No. A separate add-on for XenForo 2.0 has been released. You can support the continued development of this add-on with a donation.