the effected machine is an:

Lenovo T53 with XP Prof. SP2 latest patches. NW-Client 4.91 SP4 with
latest patches. ZEN agent

The problem:

Sometimes (!) the machine freeze after the login with the novell
client. The machine has this problem since some time, long bevor we
installed the newest clinet with patches. When I write freez than I
mean that the machine freeze after the message that a error in the
explorer.exe occurs.

The workaround we found is that the user makes a local login. And
after the local login finished he make the login over the Netware
client. If the user follows this instructions he get no problems.

But how I wrote in the beginning the problem is not everytime when the
user is loging in. The problem is sometime! And this makes this error
high mysterious.... :o(

Have anyone a idea?