pxeboot install on a toshiba 3490ct

I've made some progress trying to install NetBSD onto a toshiba 3490ct
using pxeboot.

I think I've gotten pxeboot_ia32.bin to load via tftp, then the
INSTALL_LAPTOP kernel to load via tftp.  But relatively early the
kernel hangs.  I've tried with both -current and 4.0 kernels.

The console messages look something like this:

>> NetBSD/i386 PXE Boot 1.1
>> ([email protected], Thu Jun  7 22:49:39 EDT 2007)
>> Memory 573/129920 k
Press return to boot now, any other key for boot menu
Starting in 0
PXE BIOS Version 2.1
Using PCI device at bus 1 device 4 function 0
Ethernet address 00:00:39:02:8d
net_open: client addr: 192.168.1.101
net_open: subnet mask: 255.255.255.0
net_open: net gateway: 192.168.1.10
net_open: server addr: 192.168.1.10
net_open: file_name: tftp:netbsd.INSTALL_LAPTOP.4_0
2601004+5291780+97364 [212496+200655]=0x804ccc

Then the show is over, frozen.

Any ideas what I'm doing wrong, or what I should try next?

-russ