Normally I havent had problems with checkboxes on this release (I think I did on the previous, cant remember) except for
http://mail.dhbit.ca
when it brinsg up the certificate dialog box and you click the box to ignore the problem it acts as if it instantaneously check marks it and uncheck marks it.
I am running Win2000 SP3
The latest package of the Beta (Would check the version but disabled the About menu, gotta love congifurability)