[otrs] Duplicates tickets ??

Hi, I report this problem some days ago when I was using win32. But the problem arise again under suse 10.2 with otrs 2.2.4 The problem is the system store duplicate ticket (different number with the same description) due to many cliks in create button in phone ticket screen while the system response and send a new screen. Somebody know how could avoid this problem?? Thanks Antonio Antonio