OK. Any or suggestions here would be good. Thanks in advance.

Intermittently, XP PCs take a couple of mins logging in, then a couple
logging off.

"Applying computer settings" at logon
"Running logoff scripts" at logoff

Searching forums suggest DNS issues, but what? I've switched logging
on for all areas on DNS servers, then searched the log for the IP
address of the affected PC.

This is one area that I have no idea what's going on. 10.1.1.31 is the
affected PC. What is the I.P address by "DATA" there for? It's a PC
across the WAN in a different country, which isn't even switched on.

Snd 10.1.1.31 247d R Q [8085 A DR NOERROR]
(11)company(20)company(3)com(0)
UDP response info at 013FB01C
Socket = 368
Remote addr 10.1.1.31, port 1026
Time Query=2615443, Queued=0, Expire=0
Buf length = 0x0200 (512)
Msg length = 0x0046 (70)
Message:
XID 0x247d
Flags 0x8580
QR 1 (response)
OPCODE 0 (QUERY)
AA 1
TC 0
RD 1
RA 1
Z 0
RCODE 0 (NOERROR)
QCOUNT 0x1
ACOUNT 0x1
NSCOUNT 0x0
ARCOUNT 0x0
Offset = 0x000c, RR count = 0
Name "(11)company(20)company(3)com(0)"
QTYPE A (1)
QCLASS 1
ANSWER SECTION:
Offset = 0x0036, RR count = 0
Name "[C00C](11)company(20)company(3)com(0)"
TYPE A (1)
CLASS 1
TTL 1200
DLEN 4
DATA 10.85.0.203
AUTHORITY SECTION:
ADDITIONAL SECTION: