What is your mapping syntax? could you copy/paste your login script, & what
is your server name & volume names?
make sure DS is clean & healthy
make sure you are using the latest nwclient & patches
make sure you have the server updated to the latest patches
make sure bios/firmware to everything (server/raid
cards/switches/workstations/etc) up to date
that speed/duplex on *everything* is hardset, & hardset correctly
latest drivers for everything (nic/chipset/controller/etc)
check cables, make sure everything is cat5e certified, not using flat
cables/cat3/etc (ive seen it in a lot of places)
purge all volumes & turn off compression
make sure there is more than 10% free on EVERY volume
