I have run into issues with a VFP 9 app that we have that has been upgrade from VFP 6 to VFP 9 SP1 with getting periodic "memo file is missing or invalid" error message #41 on lines of code that have "set resource to ("C:\Documents and Settings\UserName\Local Settings\Application Data\Company\Product\myprefscustomfilename.dbf"). I understand from reading that VFP 9 changed things in that it uses the resource file (otherwise known as foxuser.dbf but I use a custom name for it in the app) SHARED instead of EXCLUSIVE as it did in versions before VFP9. Whenever I want to change the data in the file in the app (since I store some data in the prefs for the custom program)
so I always use this code to update the data

set resource off
use ("C:\Documents and Settings\UserName\Local Settings\Application Data\Company\Product\myprefscustomfilename.dbf") in 0 shared alias myprefs
set resource to ("C:\Documents and Settings\UserName\Local Settings\Application Data\Company\Product\myprefscustomfilename.dbf")

any ideas on why I'm getting this and ideas on how to avoid this issue? As far as I know I've looked and the file is NOT open in any workarea when it says the error