Can't start i-Vault

After many months of successfully and happily using i-Vault all of sudden it won’t open. I get a window that just says error with an OK button. This is a major problem because I really rely on it.
Any suggestions? OS is XP-SP2-Home.
I don’t mind redownloading and reinstalling, but I don’t want to lose all my cards and have to reenter them.

UPDATE: I was having some other problems with things not working so I tried using system restore to rollback a day. The previous day’s restore point was labeled “Software distribution service 2.0”. I did the rollback and now everything is back to normal. I don’t know what happened at that restore point, but for now i-Vault is working properly.