Server 2008 64-bit - file copy crashes server

Hi
So, Windows Server 2003 SP1 had a hotfix, and it fixed the problem that the
OS uses all RAM copying large files (500MB +) and now, Windows Server 2008
SP1 has still got no wiser, but where's the hotfix??

"You may experience a decrease in overall system performance when you are
copying files that are larger than approximately 500 MB in Windows Server
2003 SP1 or in Windows Server 2003 SP2"
http://support.microsoft.com/kb/920739/

Symptoms are RAM consumption maxing out the server... SQL - paging to disk a
lot.
The OS has 8GB, of which SQL was allocated 6GB. The RAM usage grows when
files are copied - until there is no more RAM available.

OS: Windows Server 2008 64 bit SP1
SQL: SQL Server 2008 SP1
>Reporting Services also runs on this box.
>RAM: Total 8GB
>RAID 1 SAS array.