Thanks for posting.
Does this happen in a new database?
Try updating the printer drivers. These should be available on the printer manufacturer's website.
We considered the printers or printer drivers were causing a problem.
So to test this theory, on one of the computers, we uninstalled all of the printers except for the XPS Document Writer.
The print dialog still takes 45 seconds to display.
Another theory that we had was that the database has so many records and since the print dialog is set to print all records by default, then it must be preparing to print all records before displaying the dialog.
To test this theory, we made a copy of the database and deleted all but two of the records and the print dialog still takes 45 seconds to load.