ultra1 creator system freeze after terminal detach

[Stefan Bauer <duke@splatterworld.de>]

hello,

i used a windows box with hyper terminal to connect to my sun 
workstation via seriel connection (rs232). after finnished the install 
process i detached the serial connection; reason was a total system 
freeze of my box. if i restart the connection (from hyper terminal to 
sun box) i can use 'go' to reactivate the whole box and everything works 
fine.

its a sun ultra1 creator, more infos below:

Sun Ultra 1 UPA/SBus (UltraSPARC 167MHz), Keyboard Present
OpenBoot 3.25, 128 MB memory installed, Serial #8973688.
Ethernet address 8:0:20:88:ed:78, Host ID: 8088ed78.

OpenBOOT:

Release 3.25 Version 0 created 1999/12/03 11:38
OBP 3.25.0 1999/12/03 11:38
POST 3.11.4 1997/05/27 02:26

my question is now, how can i prevent the system freeze?

thanks in advance

stefan