nsgmls crash

Hi,
Trying to build the boot-floppies, I get a repeatable crash here:

slab:~# !!die_if_kernel: nsgmls(21734): Unaligned data reference 28

YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00000000000001001111111100001111

r0-3     0000000000000000 0000000000035880 000000000001f717 00000000faf00740
r4-7     0000000000033080 0000000000036342 0000000000036002 0000000000000004
r8-11    00000000000362d2 00000000000adc10 00000000000af390 00000000000b01d0
r12-15   0000000000000000 00000000ffffffff 00000000000a8ed0 0000000000000000
r16-19   0000000000000000 0000000000000000 0000000000000000 000000000001f5d4
r20-23   00000000402b0710 0000000040265970 000000000001f5d4 0000000000000000
r24-27   0000000040265970 00000000402af588 0000000040265980 0000000000033080
r28-31   0000000000000000 000000000003da00 00000000faf007c0 000000000001f717
sr0-3    000000000027e100 000000000027e100 0000000000000000 000000000027e100
sr4-7    000000000027e100 000000000027e100 000000000027e100 000000000027e100

IASQ: 000000000027e100 000000000027e100 IAOQ: 000000000001f6c7 000000000001f6cb
IIR: 4835090e ISR: 000000000027e100 IOR: 0000000000035d07
ORIG_R28: 0000000000000001

luckily all the useful bits have been built before this point. I wasn't getting this a couple of days ago, I'm keeping my system pretty much up to date with the debian archive, and don't know what upgrade introduced this problem.

Richard