Have you checked with Gmaptool your .IMGs MS flag?
If it's set to 1, have you changed it ?
Gmaptool-->Advanced options enabled-->Write Tab--> set flag in Header to 0 value--> Write all button
What are you doing? That one you call P-record is .img PID and FID. Try to read something about Garmin IMGs on forumI tried the Join-tab and create a new .img, without succes.
Is there a way to remove this P-record from the img-file ?