Working copy not updated correctly

I have a file in my working copy that doesn't appear to get updated
correctly. I have also run an svn cleanup on the working copy previously.
I've also checked out a fresh copy of the trunk and tried the same
operations and it works fine, so it looks like something in this particular
working copy is corrupt.

Does this look like a bug, or have I just done something stupid along the
way and need to start with a fresh checkout?

Cheers,
Clint

C:\wc\dbt-trunk\DCS_Software>svn st

C:\wc\dbt-trunk\DCS_Software>svn up
At revision 588.

C:\wc\dbt-trunk\DCS_Software>del DCS_Display_Unit.Uv2

C:\wc\dbt-trunk\DCS_Software>svn up
Restored 'DCS_Display_Unit.Uv2'
At revision 588.

C:\wc\dbt-trunk\DCS_Software>svn st

C:\wc\dbt-trunk\DCS_Software>svn cat DCS_Display_Unit.Uv2 > wc.txt

C:\wc\dbt-trunk\DCS_Software>svn cat -rHEAD DCS_Display_Unit.Uv2 > head.txt

C:\wc\dbt-trunk\DCS_Software>diff wc.txt head.txt
76c76
< KCADEF ()

---
>  KCADEF (DISPLAY_UNIT)
C:\wc\dbt-trunk\DCS_Software>svn diff -r550 --force DCS_Display_Unit.Uv2
svn: Delta source ended unexpectedly
C:\wc\dbt-trunk\DCS_Software>