It turns out this issue is happening due tot he fact that CBT or Change Block Tracking is not enabled on the guest OS that VADP is trying to backup. CV Support was able to provide me with a .bat file that can be used to resolve the issue on VMs running on Windows 2003. The .bat file is called vStorageBatchv5.bat. The instructions for resolving this issue on VMs running on Windows 2008 R2 are as follows
: Set the disk.EnableUUID parameter in the virtual machine settings to False by performing the following steps:
a) Power off the Windows Server 2008 virtual machine through vSphere Client.
b) Click Settings > Options >General > Configuration Parameters.
c) Set disk.EnableUUID to False.
d) Save the settings.
e) Power on the virtual machine