Document has been modified or corrupted since signed! (data)

I have modified the memo form (based on memo form from mail DB) in a custom DB so now I got the error: “document has been modified or corrupted since signed! (data)”

I got this error because the docs are signed; so how can I avoid the error message ?

thanks

Subject: document has been modified or corrupted since signed! (data)

I got the solution. I delete a sigature field

field $Sig_Untitled_Section:=@DeleteField ;