bad filter

I pass a filter string such as this to search(), but I keep getting
BAD SEARCH FILTER error.
"(|(last-login-time<=100101*)(!(last-login-time=*)))"

The same thing works when using it with ldapsearch command. I also
tried running it through ldap.filter.escape_filter_chars. Still no
luck. Is this a known bug?
I am using python_ldap-2.3.8.

Thanks