Mac Landscape mode, the future of cups?

[Jim Deas]

Got it. Time to write a filter....
I.E.
-----------------------------------------------
File of type application/pdf queued by "jdeas".
Queued on "BLD150-256" by "jdeas".
Started filter /usr/lib/cups/filter/pdftops (PID 7036)
Started filter /usr/lib/cups/filter/pstops (PID 7037)
Started filter /usr/lib/cups/filter/pstoraster (PID 7038)
Started filter /usr/lib/cups/filter/rastertogutenprint.5.0 (PID 7039)
Started backend /usr/lib/cups/backend/socket (PID 7040)
Completed successfully.
------------------------------------------------

The Mac is sending pdf, from what I have read the printer is doubling up the rotation by sending a postscript rotate command to the printer (two rotations).
The que ppd looks like a good place for prefilters but I need  a ps post filter.

Where do I tell the cups system to insert a post filter?
Shouldn't a simple script to change any ps reference from landscape to portrait 'patch' the problem?

Day one at this, am I going down the wrong path?