Report Run By Application Times Out

I am using an application that executes SSRS reports, I assume using the "Report Execution Service" (I think that's what it is called). Long running reports time out after precisely 10 minutes regardless of any timeout settings I have changed in SSRS. Is it possible that a timeout assciated with the "Report Execution Service" is over-riding any other settings? If so is there some place (such as a config file) that I can change it?

Thanks.

R Campbell