[syslinux] PXELINUX - display is 15 character wide

[Max]

Using 2.04 PXELINUX, if I boot from my machine (Serial console, DELL PV715)
The PXELINUX menu and all text shows up as 15 characters wide. Once the
memdisk is chainloaded, the screen is back to normal.

Intel PXE server works just fine.

Any ideas on how to fix this?

Thanks.

-M