According to the above post the only way to delete these sr.lock files is to completely exit all ArcGIS programs.
When attempting copy & paste of a recently used shape file (with corresponding mxd closed) this error pops up
It will paste a portion of the shape files, but not all of them.
I have both service packs 1 and 2 installed.
Anyone think Esri will have this problem fixed in 10.1?