freezes on killing ppp via ssh

[gorguth_(_at_)_tiscali_(_dot_)_fr]

hi everyone

at my office, i installed openbsd 3.6 to serve as a firewall/router.
the local network 172.16.6.0/24 is on sis0, adsl modem on sis1 (to tun0).

# cat /etc/ppp/ppp.conf                                                        
default:
 set log Phase Chat IPCP CCP tun command
 set redial 15 0
 set reconnect 15 0

pppoe:
 set device "!/usr/sbin/pppoe -i sis1"
 disable acfcomp protocomp
 deny acfcomp
 set mtu max 1492
 set speed sync
 enable lqr
 set lqrperiod 5
 set cd 5
 set timeout 0
 set authname 
 set authkey 
 add! default HISADDR
 enable mssfixup

# cat /etc/ppp/options                                                         
lock
noauth
persist
usehostname

# cat /etc/ppp/ppp.linkup                                                      
MYADDR:
 ! sh -c "/sbin/ifconfig pflog0 up"
 ! sh -c "/sbin/pflogd"
 ! sh -c "/sbin/pfctl -e -F all -f /etc/pf.conf"

# cat /etc/ppp/ppp.linkdown                                                    
MYADDR:
 ! sh -c "/bin/kill `cat /var/run/pflogd.pid`"
 ! sh -c "/sbin/pfctl -F all -d"

the problem is : 
when i connect on the box via ssh (on local net of course), if i type "kill `cat /var/run/tun0.pid`" or "pfctl -d", all freezes as locally than remotely. the only way is to shutdown the box... (ctrl-alt-suppr with machdep.kbdreset=1 fails too). that happens with the GENERIC kernel or anyone else...

did anyone see or meet the same pb ? i know that ppp doesn't need to be often killed, but it's a bit annoying...

thanx
Adrien