Slow login


I have been looking at problem of slow client login to a Win 2003 Domain.
I did a trace with Wireshark and identified two big waits.

No. Time Source Destination Protocol Info
2987 0.000067 TCP nim > netbios-ssn [ACK] Seq=182419 Ack=202615 Win=65135 Len=0
2988 19.827691 DNS Standard query SOA PC3.pctc.local

2996 43.571507 ICMP Echo (ping) request (id=0x0200, seq(be/le)=1536/6, ttl=32)
2997 0.000071 ICMP Echo (ping) reply (id=0x0200, seq(be/le)=1536/6, ttl=128)

Yes, over 1 minute wait on 2 packets! is the client and is the 2003 Server

The problem (delay) is repeatable, but not every time, so it appears to be something at the Server end.
Has anyone found this before?