Marcia, I tested the value in the debugger when I got the error and it is Ok.

Hmmm. Then something else is going on here, but I do not know what it is.

Moreover, how could you explain the fact that i got no error if I select the table with the wanted order before i perform the seek ?

Oh. I did not understand you. I thought you got the error the first time whether or not you explicitly selected the table before you did the SEEK. It is very puzzling that explicitly selecting the alias solves the problem, but if it solves the problem, well - shipping is a feature < s >.

The fact that the error does not occur when you step through the code in the debugger makes me think that this might be a timing issue. What happens if you put a DOEVENTS in front of the SEEK?