Help!- unable to initialize security subsystem? -NT

I am running Informix On-line workgroup server v. 7.22 on NT 4.0 and Netscape Enterprise Server 3.0. Running some web/database apps. Everything is going fine for the past 6 months and then suddenly the Informix services will not load with this error in the event log: Could not initialize the security subsystem. Please ensure that this account has the necessary privileges. The account informix does have permissions to "run as a service", "act as a part of the operating system", and "create a token object". It is part of the Informix-Admin group. These are the requirements for the informix account according to the manual. The on-line center reports the database is off-line and when I try to make it on-line I get the same error message. I have tried: re-installing informix, re-entering the informix account and re-applying security permissions to the informix directories. Any help? Thanks. Marc Doolittle marcd@webquiz.com