5.99.23 UP enters in deadlock

[BERTRAND Joel <joel.bertrand%systella.fr@localhost>]

        Hello,

	I'm trying to build userland to make some tests and UP kernel randomly 
enters in dead lock. For example, my SS20 tries to build xsane from 
ports and ./build.sh -O ../obj -T ../tools -U -u distribution.
All processes stop without any other information. System is idle, but I 
cannot launch any other command :

^CRoot riemann:[/usr/src/src] > top
^C^C^C^C^C^C^C

	This SS20 runs with a RT626, but if I remember, I have seen the same 
trouble with SM71.

load averages are:  5.03,  4.81,  3.85 with no running process.

        Regards,

        JKB