[Hampshire] FC8 dependency circularity

Hi all and a much belated happy new year

Having fun with FC8 this morning. I've only recently got it up and running
and unsurprisingly it now wants to update 420 odd packages. I thought -
why not - and told it to do so all at once. Another unsurprising result -
dependency conflicts. Trouble is - two of them - I can't resolve and my
FC8 inexperience is stopping me working my way around it.

The two in question are firefox and xulrunner. I've unchecked both in the
list of updates but I'm still getting:

file /etc/gre.d/gre.conf from install of xulrunner-1.9-0.beta2.7.fc9
conflicts with file from package firefox-2.0.0.8-2.fc8

I maintain that the xulrunner box in the package updater is unchecked.
However - those that are checked may well be downloading xulrunner - and
there's no easy way I can find to identify which package is doing this.
When I click apply, it asks to download some others.

I'd rather uninstall firefox which seems to be the culprit - is this the
best solution?

Cheers
Rob