Hello.
I'm getting the following block on a couple of sites that use Moodle:

Sat Jul 31 13:03:16 2010] [error] [client 85.54.146.59] ModSecurity: Access denied with code 406 (phase 1). Match of "rx ^((?:(?:POS|GE)T|OPTIONS|HEAD))$" against "REQUEST_METHOD" required. [id "960032"] [msg "Method is not allowed by policy"] [severity "CRITICAL"] [uri ""] [unique_id "8ZJS6ECDSyoAAD7JhSQAAAAK"]
[Sat Jul 31 13:03:20 2010] [error] [client 85.54.146.59] ModSecurity: Access denied with code 406 (phase 1). Match of "rx ^((?:(?:POS|GE)T|OPTIONS|HEAD))$" against "

This is really causing a problem. 
Any ideas on how to stop this happening would be appreciated. 
I have very little idea about Mod Security. 
Thanks.
Alistair
BTW, I couldn't see how to search the archives - apologies if this has already been posted.