Genius Bar + Custom UI

I recently took my MBP into an Apple store because it froze 3 times in a row while using text edit. It froze a 4th time

The genius I saw said he could not service my machine because I had a custom dock installed. This is somewhat understandable because it requires authorization and deletion of system core service files. He showed me the disclaimer for jail broken iPhones, but I said this was different because you don't need a third party program to change the dock.

However, he also mentioned that the fact I had customized many icons (something that you can do via the built-in copy and paste function) rendered the machine unserviceable. He even went so far as to suggest that replacing icons were the cause of freezing.

I said I didn't think the icons were a problem - like blaming racing stripes if your engine wont start. He said I should wipe and reinstall.

Has anyone else had problems with custom UI at the genius bar?