Moving from PXE to gPXE causes fatal error: 10 (out of resources)

Folks,

I have four servers with 16Gb RAM for which I had a PXE install environment.  The PXE environment used DHCP, TFTP, PXE and then HTTPD for kickstart.

All four servers instaled correctly every time.

I switched to using gPXE so that I could install ESXi via HTTP.  I used cobbler (with some recent patches) to setup the gPXE environment.

I can get the ESXi servers to boot into the installers and start to download some modules.  But when I hit the tools module (which is about 150Mb) I get

"fatal error: 10 (out of resources)"

Does gPXE limit memory in any way ?   My only change was to switch from PXE to gPXE.

Is there a way to see exactly which reosurce ESXi is out of ?

I would post detailed configs, but I an trying to see now if there is a general answer.

Thanks

John