WHS Backup Blues
I have not been very happy with WHS lately - and the backups have been failing as you can see in the two screen shots below. 
Looking at the event log there have been many errors. I have not had the time to research these and see what is wrong. Here is a sampling on what is going on:
Event Type: Error
Event Source: Application Error
Event Category: (100)
Event ID: 1000
Date: 25/08/2007
Time: 02:57:39
User: N/A
Computer: TRINITY
Description:
Faulting application whsbackup.exe, version 6.0.1424.2, faulting module whsbackup.exe, version 6.0.1424.2, fault address 0x00056e8e.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 41 70 70 6c 69 63 61 74 Applicat
0008: 69 6f 6e 20 46 61 69 6c ion Fail
0010: 75 72 65 20 20 77 68 73 ure whs
0018: 62 61 63 6b 75 70 2e 65 backup.e
0020: 78 65 20 36 2e 30 2e 31 xe 6.0.1
0028: 34 32 34 2e 32 20 69 6e 424.2 in
0030: 20 77 68 73 62 61 63 6b whsback
0038: 75 70 2e 65 78 65 20 36 up.exe 6
0040: 2e 30 2e 31 34 32 34 2e .0.1424.
0048: 32 20 61 74 20 6f 66 66 2 at off
0050: 73 65 74 20 30 30 30 35 set 0005
0058: 36 65 38 65 6e8e
Event Type: Error
Event Source: HomeServer
Event Category: Backup
Event ID: 272
Date: 25/08/2007
Time: 02:56:47
User: N/A
Computer: TRINITY
Description:
Unexpected error 0x45d from WriteFile on D:\folders\{00008086-058D-4C89-AB57-A7F909A47AB4}\Data.4096.16.dat: The request could not be performed because of an I/O device error.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Event Type: Error
Event Source: HomeServer
Event Category: Backup
Event ID: 267
Date: 25/08/2007
Time: 02:56:47
User: N/A
Computer: TRINITY
Description:
Client Backup server failed at d:\qhsv1_rc\qhs\src\backup\util\diskfile.cpp(421)
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.