I was having some stability problems on 7.3, so I just did a fresh installation of 7.3 on my Mac (running OS 10.4.11 on an Intel 2 x Dual 2.66 GHz Mac Pro) and verified that everything worked. Then, I installed the 7.5 update, but when I tried to open the application, I got the message "You cannot open the Application 'QuarkXPress' because it is not supported on this architecture". The system requirements seem to indicate that my system is perfectly acceptable. Has anyone else had (or, more to the point, FIXED) this problem?
For the time being, I will clear out 7.5 and reinstall 7.3 and just upgrade to 7.3.1.
Thanks!