Are you sure that it was the uninstallation of mIRC that caused this problem? After you uninstalled mIRC, did you reboot your system? Have you verified that your system is virus free?
Did you install anything between the time that you uninstalled mIRC and when you noticed this problem?
Those are the first things I'd be checking, as mIRC has nothing to do with your webbrowser or e-mail client (with the possible exception of if you had one or more scripts that interfaced with those items).
