Batch File Doesn't Run In Particular Directory

I use a batch files for various maintenance stuff.Get this: When the batch file (.bat or .cmd), is in ONE PARTICULAR DIRECTORY, the defrag command in it echos endlessly, but doesn't execute. Even if the batch file contains only just the one line.If the batch file is in any other directory, it works fine. Of course, I keep all my batch files in the same directory ("C:Program FilesBruce"), and I can find nothing anywhere in Windows that should cause this directory to be any different than any other. Addition a few minutes later: Now the simple one-line batch file will sometimes work, sometimes not work, when in other directories. This is weird.