0xe00084af failure on a local backup of server.

I am getting the dreaded 0xe00084af - the directory or file was not found, or could not be accessed. Final error category: Job Errors. For additional information refer to link V-79-57344-33967
This link doesn't help as I am not running a remote x64 Sav10 (it is local and not x64), I am not running Continuous protection, I don't use DFS, It's a local server not Linux and Advanced file option turned off also provides the same error.

The server backs up to lto tape (which was recently replaced at the time the error started to occur in case this is relevant - replaced as the tape snapped in the drive).
A backup of remote servers to the same hardware in a different job works fine.
I tried creating a new job to backup (any) one file on the local C (only one drive) , that i  know is not in use and get the same message. Turning on or off the Advanced File Open option doesn't solve the problem either.
Running 10.0 service pack5 (it was running without service pack and I upgraded to 5 to see if that would help - it didn't).
Server also has exchange agent which works too (from another server)
Server has been rebooted and problem still occurs.

vss list writers does not show any problems - all of them come up as stable no errors - details below in case this helps.

C:\Documents and Settings\Administrator.DOMAIN>vssadmin list writers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line too
(C) Copyright 2001 Microsoft Corp.

Writer name: 'System Writer'
  Writer Id: {e8132975-6f93-4464-a53e-1050253ae220}
  Writer Instance Id: {a66599a1-aeb5-481d-9591-67cb8879af66}
  State: [1] Stable
  Last error: No error

Writer name: 'FRS Writer'
  Writer Id: {d76f5a28-3092-4589-ba48-2958fb88ce29}
  Writer Instance Id: {2cc91f70-0f60-43ca-8215-542a99457c31}
  State: [1] Stable
  Last error: No error

Writer name: 'SqlServerWriter'
  Writer Id: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}
  Writer Instance Id: {1618f0f8-0301-4c17-a595-d218f9a08664}
  State: [1] Stable
  Last error: No error

Writer name: 'MSDEWriter'
  Writer Id: {f8544ac1-0611-4fa5-b04b-f7ee00b03277}
  Writer Instance Id: {d219e89a-12a3-4b7e-b4a0-235ada8f00f3}
  State: [1] Stable
  Last error: No error

Writer name: 'Registry Writer'
  Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}
  Writer Instance Id: {e9182c5b-0b75-44bf-bdaf-875b02487924}
  State: [1] Stable
  Last error: No error

Writer name: 'Event Log Writer'
  Writer Id: {eee8c692-67ed-4250-8d86-390603070d00}
  Writer Instance Id: {690d9b54-9266-4ca9-8c3b-68ea639cfa4e}
  State: [1] Stable
  Last error: No error

Writer name: 'IIS Metabase Writer'
  Writer Id: {59b1f0cf-90ef-465f-9609-6ca8b2938366}
  Writer Instance Id: {428a3a7a-ce7d-42a6-8574-eb8c301990a8}
  State: [1] Stable
  Last error: No error

Writer name: 'COM+ REGDB Writer'
  Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}
  Writer Instance Id: {47649ba7-1477-4e01-963d-aabb4e83b09b}
  State: [1] Stable
  Last error: No error

Writer name: 'Dhcp Jet Writer'
  Writer Id: {be9ac81e-3619-421f-920f-4c6fea9e93ad}
  Writer Instance Id: {48a6ac2f-0b3e-424a-849a-0c885799077d}
  State: [1] Stable
  Last error: No error

Writer name: 'NTDS'
  Writer Id: {b2014c9e-8711-4c5c-a5a9-3cf384484757}
  Writer Instance Id: {1854a6a7-8226-4d01-99bd-16526f440b72}
  State: [1] Stable
  Last error: No error

Writer name: 'WMI Writer'
  Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0}
  Writer Instance Id: {e7c3e279-cb70-47d9-a627-7f617bb4ce9a}
  State: [1] Stable
  Last error: No error

Writer name: 'Removable Storage Manager'
  Writer Id: {5d3c3e01-0297-445b-aa81-a48d7151e235}
  Writer Instance Id: {0031e50f-6f79-4fda-828e-d04c5407daa2}
  State: [1] Stable
  Last error: No error

Writer name: 'BITS Writer'
  Writer Id: {4969d978-be47-48b0-b100-f328f07ac1e0}
  Writer Instance Id: {dbd0dfb0-6a0d-464c-abec-e87e88177b50}
  State: [1] Stable
  Last error: No error


Seeing as though this server holds all the users shares and company data, it is critical that this server gets backed up.

Not sure what other information I can provide - let me know!