I use a Brother HL 1270N, my printer can print in 4 modes:
HP Laserjet 6 (PCL), BR-Scriptlevel2, Epson FX-80, IBM Proprinter XL.
You can set the emulation via a web interface e.h. http://<printer ip address>/printer/main.html. This should match the driver installed.
It seems you have the wrong driver installed for CUPS or the remreo server is misinterpreting it.