It's been my experience that the 'classic' French souffles do collapse rather quickly. You know the Italian expression 'the pasta waits for no one' - meaning you need to have your sauce ready and your guests at the table by the time the pasta is ready! Same with souffles - everyone should be at the table;, forks in hand, as you bring the souffle to the table!
The only other problem spots usually are the pan preparation, and how the whites are beaten.
I just found a fantastic site from PBS, the 'Jacques and Julia' series, where you can see a video of them preparing a lobster souffle -
This whole series is an absolute gem of knowledge!