Open or Save as Prompt in IE

[Brian07]

I'm integrating an image viewer from a filenet database into an ASP app we currently support. When a user retreives a document for viewing from the database, the user gets the usual Open, Save, Cancel, More Info prompt. The little check on the box "Always ask before opening this type of File" does nothing to prevent the pop up from launching again in the future. Is there an option related to Win 2k/XP/NT 4.0 that will suppress this pop up?