I Assume that your attemting to send some information in the message body of the sendobject command, which then removes the automatic signature! The Method i use is to send any information as an attachment and leave the message body clear, then the signature reappears, and it's not too much to ask the user to type there own message say what is attached, after all there suposed to do something!! Heres the format -
Docmd.SendObject acReport, "RepReportName", "Rich Text Format (*.rtf)", "E-mail Address", "CC", "BCC", "Mail Title", "Message Body", False
I Know this isn't exactly what your looking for but it may do instead, if you do find a way to get the signature on when putting anything in the message body pass it on
HTH
Mitch.