There is a well known bug in PageSetupDialog in Framework 1.0 when using metric measurment system:
For example show the pagesetupdialog and set the left margin to 25.4 mm (1 inch) and press ok. Now show it again and the value is now 10 (divided by 2.54 to be converted to inch and set the print document margin which is measured by 0.01 of inch, but not converted back to mm at subsequent ShowDialog).
It is known for a long time now and there is a work arond for it but I hoped that it will be fixed in 1.1, but it's still there. I wonder why!