Send print from windows 7 to printer at windows XP changes the format of the spool file

Question

I have this weird problem

I have a printer installed at windows XP and I configured the print processor like this "winprint---> NT EMF 1.003"

So the .spl file is an EMF Format file.

Now i share this printer to my office lan.

When I send a print from another windows XP pc there is no problem.

When I send from a windows 7 pc, the .spl file is in pcl3 format. why?

I try to install this printer to windows 7 pc with two methods.

a) Add Printer--> A network printer or a printer attached to another computer. In this case when i print, a .spl file is created only in windows XP machine, in pcl3 format.

b) Add Printer--> Local printer attached to the computer. I create then a new Local Port, that is the network path to the shared printer. In this case when I print a .spl file is created in windows 7, that is EMF format!!!!!!, and another one in windows XP, that is pcl3 format.

Why is this happening? I want when i print from windows 7 to the share printer, to create an emf format .spl file in windows XP.