For a while now I've been experiencing trouble with trying to back up our server using the built-in server backup tool: It would fail for some reason about a shadow copy, but would work if I just chose to do the individual drives (C:, D:).
Lately though, it has started acting up and is now failing out of the blue with this:

I don't know what's causing it, and I've been searching around on Google but haven't had any luck with it.
For more information, here's a couple of snaps from the event log that might be of help:


And finally, an XML dump from picture 3's details window:
Log Name: Microsoft-Windows-Backup Source: Microsoft-Windows-Backup Date: 6/10/2013 7:20:39 AM Event ID: 5 Task Category: None Level: Error Keywords: User: SYSTEM Computer: ****** Description: The backup operation that started at '2013-06-10T12:19:26.203012000Z' has failed with following error code '2147942487'. Please review the event details for a solution, and then rerun the backup operation once the issue is resolved. Event Xml: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Microsoft-Windows-Backup" Guid="{1DB28F2E-8F80-4027-8C5A-A11F7F10F62D}" /> <EventID>5</EventID> <Version>2</Version> <Level>2</Level> <Task>0</Task> <Opcode>0</Opcode> <Keywords>0x4000000000000000</Keywords> <TimeCreated SystemTime="2013-06-10T12:20:39.944212000Z" /> <EventRecordID>262</EventRecordID> <Correlation /> <Execution ProcessID="7992" ThreadID="5672" /> <Channel>Microsoft-Windows-Backup</Channel> <Computer>******</Computer> <Security UserID="S-1-5-18" /> </System> <EventData> <Data Name="BackupTemplateID">{99B0DB5B-0D9C-4104-B80A-CB0DA8E1A81F}</Data> <Data Name="HRESULT">2147942487</Data> <Data Name="BackupState">12</Data> <Data Name="BackupTarget">Q:</Data> <Data Name="NumOfVolumes">2</Data> <Data Name="BackupTime">2013-06-10T12:19:26.203012000Z</Data> <Data Name="HRESULT2">2147942487</Data> <Data Name="VolumesInfo"><VolumeInfo><VolumeInfoItem Name="C:" OriginalAccessPath="C:" State="15" HResult="-2139619228" DetailedHResult="0" PreviousState="0" IsCritical="1" IsIncremental="0" BlockLevel="1" HasFiles="0" HasSystemState="0" IsCompacted="0" IsPruned="0" IsRecreateVhd="0" FullBackupReason="0" DataTransferred="0" NumUnreadableBytes="0" TotalSize="0" TotalNoOfFiles="0" Flags="1544" BackupTypeDetermined="0" SSBTotalNoOfFiles="0" SSBTotalSizeOnDisk="0" /><VolumeInfoItem Name="D:" OriginalAccessPath="D:" State="15" HResult="-2139619228" DetailedHResult="0" PreviousState="0" IsCritical="0" IsIncremental="0" BlockLevel="1" HasFiles="0" HasSystemState="0" IsCompacted="0" IsPruned="0" IsRecreateVhd="0" FullBackupReason="0" DataTransferred="0" NumUnreadableBytes="0" TotalSize="0" TotalNoOfFiles="0" Flags="8" BackupTypeDetermined="0" SSBTotalNoOfFiles="0" SSBTotalSizeOnDisk="0" /></VolumeInfo></Data> <Data Name="DetailedHRESULT">0</Data> <Data Name="SourceSnapStartTime">2013-06-10T12:19:26.187412000Z</Data> <Data Name="SourceSnapEndTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="PrepareBackupStartTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="PrepareBackupEndTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="BackupWriteStartTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="BackupWriteEndTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="TargetSnapStartTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="TargetSnapEndTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="DVDFormatStartTime"><TimesList></TimesList></Data> <Data Name="DVDFormatEndTime"><TimesList></TimesList></Data> <Data Name="MediaVerifyStartTime"><TimesList></TimesList></Data> <Data Name="MediaVerifyEndTime"><TimesList></TimesList></Data> <Data Name="BackupPreviousState">2</Data> <Data Name="ComponentStatus"><ComponentStatus></ComponentStatus></Data> <Data Name="SSBEnumerateStartTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="SSBEnumerateEndTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="SSBVhdCreationStartTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="SSBVhdCreationEndTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="SSBBackupStartTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="SSBBackupEndTime">1601-01-01T00:00:00.000000000Z</Data> <Data Name="SystemStateBackup"><SystemState IsPresent="0" HResult="0" DetailedHResult="0" /></Data> <Data Name="BMR">false</Data> <Data Name="VssFullBackup">false</Data> <Data Name="UserInputBMR">false</Data> <Data Name="UserInputSSB">false</Data> <Data Name="BackupSuccessLogPath"> </Data> <Data Name="BackupFailureLogPath"> </Data> <Data Name="EnumerateBackupStartTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="EnumerateBackupEndTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="PruneBackupStartTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> <Data Name="PruneBackupEndTime"><TimesList><Time Time="1601-01-01T00:00:00.000Z" /><Time Time="1601-01-01T00:00:00.000Z" /></TimesList></Data> </EventData> </Event> I am not sure if this is entirely useful - if additional details are needed, please let me know and I will append them to this as they become available by request.
EDIT: Forgot to specify some basic but important information:
OS - Windows Server 2008 R2 Standard, Service Pack 1, 64-Bit