I am sure that someone like Mark will explain the reasons for this fix in particular when he sees your post. The only other solution given in the past is to get moved to the insecure server - but I am sure that it is more preferable for you just to use the disable mod_security solution.
I am unsure how much information that eUKhost can provide about the mod_security rules without compromising the security of the server but I am sure they will give you as much information as possible.
