The suggestion for rehearing en banc is granted. The opinion and judgment of the panel, previously filed, are vacated. This case is set for oral argument before the Court en banc in St. Paul, Minnesota, on Monday, May 11, 1992.

The parties are invited, though not required, to file supplemental briefs, not to exceed 15 pages, the briefs to be filed simultaneously on or before April 20, 1992.

It is so ordered.