After I complete a client, successful efile, and all other aspects of the return are complete, I lock the file.  I've done this since using ProSeries and never had an issue.  This year, its been a challenge and I normally receive this message:

"Lock client operation failed.  An error occurred while saving **bleep** client file"

Normally, if I wait a while (or if I close the program and then restart) it will normally lock...not always though.  Anyone else having this issue?