I get this error when I do an svn update:
Working copy XXXXXXXX locked Please execute \"Cleanup\" command
When I
For me, it was actually Tortoise's fault, sort of. Tortoise just complained "cannot clean up, run clean up", but when I ran the command line (svn cleanup), it clearly told me that it couldn't delete some files that were in use, the solution to which was obvious. Once I closed Visual Studio (which was keeping the files open), then the cleanup worked fine.
Other programs can also keep files open in the repo causing this issue. Excel holding an xls open was a culprit in another instance so it may be wise to close all programs that may be using anything in the repo or even rebooting to force programs to close out and then trying cleanup again.