Can not take Snapshot backups seems to be the prevelant accepted answer but how do you reconcile that with the following from BOL fpr 2005
ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/udb9/html/9b5720a9-93df-421f-b854-33e4656762e0.htm
Quoting from the above BOL entry:
SQL Server snapshot backup is accomplished in cooperation with third-party hardware or software vendors, or both. These vendors use SQL Server 2005 features that are designed for this purpose. The underlying backup technology creates an instantaneous copy of the data that is being backed up. The instantaneous copying is typically accomplished by splitting a mirrored set of disks or by creating a copy of a disk block when it is written. This preserves the original. At restore time, the original is made available immediately and synchronization of the underlying disks occurs in the background. This results in almost instantaneous restore operations.
and
Only the following types of backups can be snapshot backups:
Full backups
Partial backups
File backups
Differential database backups