Quark Xpress 9 crashes at startup

I have installed Quark Xpress 9.3 on my MacBook Air with 10.7.5 and it does not start. It freezes at startup and needs a force quit. Very helpful, Quark Support, after many tries, made me create a root disk, from where the application finally starts up. The problem should be a conflict with some of the applications I have on my HD. Has anybody had a similar experience? Any suggestion for an application wich might create such a conflict? Thanks