Layout text moves between PC and Mac

We generate multi-panel figures for papers using layouts. Each panel is a graph, and then we lay them out and label them (A,B,C,...) with textboxes in the layout. This works great, but then I replaced my PC with a Mac, and now when I trade experiment files back and forth with my lab (who all use PCs), for some reason, the graphs in the panels stay where they should, but the textboxes all shift, usually it seems to the top left of the layout. Any ideas what's going on? Work-arounds?

-Matthew
When you move between platforms Igor may do font substitution. The text on the new platform may be different in size from the original platform causing differences in annotations.

For example, I did this on Macintosh:
Layout
TextBox/C/N=text0/M/A=LB/X=29.09/Y=83.06 "\\Z72Test"


On my system this positions the annotation flush against the bottom/right corner of the page (dotted line).

When I move this to Windows it is still flush against the bottom edge of the page but not flush against the right edge. This is because Igor has substituted Arial for Geneva and Arial generates narrower text. If I change the font to Arial on Macintosh then the annotation position is identical.

If this does not explain the problem then I would need a reproducible case. It would be best to provide a simplified experiment file. Also include your OS and Igor versions.