Thanks for all of the great information. The company we purchased it from is no longer in business - of course. We'd had problems a year ago and a repair guy came and looked into it and fixed it. He handled it through Hydropool warranty. I've talked with him and he is trying to get Hydropool to warranty this - so far it is a no go. Our warranty info says: shell 10 yrs limited warranty, interior surface 3 yrs limited, labour 3 yrs , etc.
We purchased it late 04 and it was delivered Jan 05. So there you have it.