Symptoms
Checked out documents
Diagnoses
cannot edit documents once checked out
Resolution
When you edit a file in the office clients they 'lock' it to prevent concurrent editing. The lock itself is supposed to expire, but while it is still locked, you won't e able to edit it. This is a parallel system to Check-Out - so you can have a locked file that isn't checked out. Confusing?
I think of the lock as being an automatic 'check-out' by Office, rather than a normal 'manual' check out.
There is a short description of this here - think4code.blogspot.co.uk/.../sharepoint-2010-file-is-locked-for.html
Wait for 10 min for lock to expire (this is true in 80 % of cases)
