[BNM] friendly urls bomding out

[Ali]

hey I am having a bit of a nightmare with a friendly url system I have botched together using .htaccess to redirect 404 requests to a URLengine php script

works a treat in firefox and safari but a very high percentage of the time is bombing out to a 404 page with IE6 and IE7 - what gives?? how can this be browser specific? anyone had this before? it's like the .htaccess directive is being ignored when using IE - eh?

any help greatfully received

ali