Problems in first boot

["Roberto A. F. Almeida" <roberto@calvin.ocfis.furg.br>]

Greetings,

I'm having trouble installing OpenBSD. I tried to install OpenBSD 2.8 in
two different computers (an AMD K6-II 400, 128 Mb, 8 Gb; and a Pentium 200
MMX, 64 Mb, 6 Gb), and in both I got the same error in my first boot after
the install:

(...)
isadma0 at isa0
extent_alloc_region: extent 'ioport' (0x0 - 0xffff)
extent_alloc_region: start 0x400280, end 0x40029f
panic: extent_alloc_region: region lies outside extent
Stopped at    _Debugger+0x4:   leave
ddb >

The HD was partitioned in the following way:

a /       80 Mb
b swap    256 Mb
d /tmp    80 Mb
e /var    80 Mb
f /usr    1 Gb
g /home   rest

Any hints? TIA.

Roberto