Vista - Slow network browsing in Vista

Hi,

Vista Business with SP1
Brand New Dell Latitude D531 with Dual Core Turion CPU and 4GB RAM
Computer domain client under Win2003SP2 R2 domain controllers

When opening the home folder in Explorer a few of its folders display
immediately but folders with many subfolders or files takes several
seconds to open and display. This is very annoying and it does not seem
that Vista caches this information as it takes the equal amount of time
when I do the same operation seconds later.

XP does this immediately for the same user account.

We have applied all the 'well known' netsh settings suggested as cures,
but to no avail. Note that we are already running SP1.

Any other thoughts on this issue?

rgds geir