If you review the LiteSpeed forums you'll find that there's actually quite a bit of talk about the lack of support for mod_security in their software. LiteSpeed created their own module which is supposed to support the mod_security rules.
If you want 100% compatibility with mod_security, you will want to stay with Apache.
Just additional (hopefully useful) info - Configserver has great tool to enable/disable particular rule(s) for any account or list of accounts with the easiest way by using their Configserver Modsecurity Control plugin, freely available here - http://configserver.com/cp/cmc.html
It makes everything easy
__________________ EURO-SPACE - Reliable Hosting Solutions Since 2007