Although I don't personally know what the limits are, there is a limit to the INI file size.

The good news is, there is a UDF that removes this limit and works every bit as good.

Please see IniArray, and it's children ReadIniArray, and WriteIniArray here:
http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Number=202790#Post202790

How to use UDFs -
http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Number=81943#Post81943

The rest of the UDFs are here -
http://www.kixtart.org/forums/ubbthreads.php?ubb=postlist&Board=7&page=1