Harry,

similar things have happened to me. I think that this error 41 is triggered when the fpt file is sometimes only so slightly corrupted that it doesn't matter much. In a recent case the exe triggered error #41 and the user couldn't open the table in EXCLUSIVE mode, but was able to open it in SHARED mode. So, my index reconstruction utility wouldn't work for that table. When I got the table that had the problem, I could open it in the Command window either in SHARED or EXCLUSIVE mode with no problem. But I put that file in a place where the exe would use it and the exe had the same problem the user had with opening that table exclusively, it generated #41 and wouldn't open. I ran a utility called dSalvage on it and dSalvage couldn't detect the memo file corruption. So, I just created a different table with same exact data structure, COPY STRUCTURE TO .. WITH CDX, and then appended all the data into the new table, then replaced the old one and everything worked fine after that.

You would've gotten good answer sooner except that you asked question on July 4'th.

Wally