[jQuery] Unexcpected Quantifier in IE6 (1.2.1 & SVN)

The problem is occurring on line 822 (from the current SVN code),
/^\[ *(@)([a-z0-9_-]*) *([!*$^=]*) *('?"?)(.*?)\4 *\]/i,
It only throws the error in IE6, I have been led to believe it is
something to do with *, but I am unfortunately totally regexp
retarded. Any insight would be appreciated.