"one or more accessor flags were invalid"

I use MS SQL 2005 with a linked server to a visual Foxpro table (DBF) with VFPOLEDB provider. I creare a stored procedure with a filter and when I execute it I receive the result table correctly filtered. If I use a parameter on the same procedure I receive an error message: "one or more accessor flags were invalid"
Why ?

[328 byte] By [itmanager] at [2007-12-17]