Previously I was ale to extract the disk image from the zip file but VMware Server complained that the disk image was corrupeted and would try to fix it but this never seemed to work.
Checkpoint seem to have fixed the corrupted disk image now but the vmx config file provided doesn't work or at least didn't for me in VMWare Server 1.0.1 on Ubuntu Linux 6.06.
Creating a new config from scratch using RedHat Enterprise Linux 3 (Which SecurePlatform NGX is based on) and using LSI Logic as the SCSI adapter type worked for me. Ignore the note about VMnet3 in the readme file and just sent it to used bridged networking and it works fine from any host in the 192.168.1.x range which allows you change the IP address to whatever you use.