thanks for the posts, I did resolve the problem by removing mod_perl2, which is a shame as I was starting to get into mod_perl.

The problem was not with a mod_perl script but a cgi script so there should not be any problem with variable declaration, I only had 1 mod_perl script which worked fine.

The problem was definately not a browser problem I reproduced the error on 3 platforms and several browsers.

Since having no more errors since removing mod_perl2 I am leaning towards the "funkyness between CGI.pm and mod_perl" theory from the link in my original post.

I can reproduce the error on my devlopment machine so will try to figure it out once I have some spare time.