safari launches program unexpectedly

I've done some tests on my wife's MacBook Pro.

1. With Citrix 10.0 installed (existing), Safari shows normal behaviour on www.espncricinfo.com i.e. does not launch the Citrix plugin.
2. I've since installed Citrix 11.2 and Safari again behaved fine.
3. I've also launched my work connection which invokes the plugin to let it set some Preferences. Then tried the www.espncricinfo.com site again and it seems to work fine.

So the conclusion is that I must have something corrupted in my settings somewhere.

Good info - I'd try swapping preference files next, myself. Or renaming/swapping so that you can revert if things don't go well.
Use Find any File , but if it affects all users you're probably looking at HD/Library/Preferences/ or HD/Library/ApplicationSupport/

My Air is a single user computer. I've removed the Safari plist file but the problem persists. Also started in Safe mode - same result.

Where the computers do differ other than hardware is that on my wife's MBP, I have Flash installed for Safari whereas on the Air, I do not have any Flash. Google Chrome has Flash built into the core. I'm wondering if this may be a reason. I suppose I can install the Flash plugin, but I don't wish to do this. I'll stick to Chrome which has become my default browser. Not too pleased that they won't be supporting h.264 natively in future as I don't really like to invoke plugins. But that is another story.

Thanks for your help, I'm sure I'll be asking for some in the future whilst I try to resolve this issue.

I unhid the /private/var... directory, via Terminal, so do now know where it resides. Don't know if I can delete the entire Directory where the Citrix*.ica files reside.

For what it's worth, I also had this problem, only with the soccernet.espn.go.com website. I'm running a new 15 inch MacBook Pro without flash. Like ESPN's other properties, Soccernet has lots of flash sprinkled throughout the page. Using Safari with Citrix installed, it randomly tried to launch Citrix whenever I navigated to Soccernet. Without Citrix installed, I got "Missing Plugin" boxes where the flash boxes normally would be. It also seemed to me that other sites with flash ads were running slowly, although that could have been my imagination. As the problem didn't present itself in Chrome, I suspected that the way Safari handles the missing flash plugin had gotten screwed up. After reading this thread, I used OnyX to rebuild my LaunchSerivces and that seems to have done the trick. No more attempted Citrix launch when navigating to Soccernet and now I have static ads or questionmark boxes in the flash boxes. Many thanks for this thread.

I've tried rebuilding my Launchservices - but still getting same error unfortunately.