Can't copy a large file from XP share

I can't copy from an XP share to a Vista SP1 laptop actually two
different laptops. The limit seems to be 20 Meg for a wireless and
around 100 Meg for a wired connection, almost as if there is a 'time
out' on the copying time. The limit is reached whether it is one file
or many files. When the limit is reached, any files below the limit
will copy correctly. After the limit is reached, the 'Retry' window
will popup. If 'Retry' is pressed, it will copy another limit's worth
of files.

The source XP system is in a windows Workgroup, XP Professional SP2
with the LinkLayer update for Vista added.

The destination system is a brand new Vista Home Premium with SP1
preinstalled. The network adapters were updated with the latest
drivers.

When the firewalls and all AntiVirus are disabled, the problem still
occurs.
The windows accounts and password match on both systems.
Sharing is turned on and Everyone has read permissions.

On both Vista, file sharing on or off makes no difference
Also, password protection on or off makes no difference.
The transfer quota is set to unlimited.
Windows firewalls are turned off.
The router is a D-Link DIR -655.
When attempting a wired copy, the wireless is disabled.

XP to XP copies work fine. And from Vista to XP works fine (opposite
direction), as does Vista to Vista.


Any help would be appreciated.

Thanks in advance
-R