I have XP SP3 workstations, with 4.91.5 clients, ZEN 7.0.2 with latest agent
NMAS enabled

I have something that I can not understand.

DLU, LDAP returns the correct OU instantly when the user types name & presses tab.
Password is filled, OK is pressed & mostly the client login window sits there ~ 30 -50 seconds with hourglass going in circles & only after that time desktop starts showing, till the moment Zen Application Browser finished all startup items it is anything between 1 min 30 to 6 min (depending on PC)

I was playing with unchecking MS networking, uninstalling it, disabling services, like Server & Computer Browser, setting NMAS authentication to OFF

Yet I can NOT get any consistent behaviour.
Sometimes with some things off/disabled I can get full login in 1 min 28 sec
On a couple of occassions I had it in under 58 sec (what I am aiming for really)

But could never duplicate (each next login on same PC with same user gives different time)

I am at loss what else to do.

Wireshark captures do not show anything obvious

Anybody has any ideas how to start tacking it?