I know how these guys feel. I've been doing a lot of application compatibility work lately myself on Norton Online Family. It's really important that the software works well and interacts well with other Symantec software as well as other software including IM clients, web browsers, internet security suites, personal firewalls, etc.
The interplay and intertwining of these applications can get really interesting when you start getting into API hooking and driver level code where IO requests are being processed and you're passing through filter drivers of other suites, etc. Fun to debug!
It makes me thankful for VMWare and kernel debuggers :)