Why doesn't schedualed Defrag run

[chasgl]

The Disk Defragmenter dial box says
Run on a schedule (selected)
Run at 1: AM every Wednesday at 1: AM starting 11/21/2008
Next scheduled run : Never
Why would that be? How can I fix it?
Thank,
Chas

 

[chasgl]

Thanks, Yes I leave the machine and am usually in bed by then. But it
doesn't even say anything is scheduled for the future.
Strange,
Chas

 

[chasgl]

Good idea. I tried it, It showed that it would defrag just when I expected
it. I forgot to close the screen. 10 minutes later it said next scheduled
defrag : never. So I went into a endless loop. Set if for a different day of
the week : things look OK. Close window, look again it says next scheduled :
never. So I am giving up. Thanks again for your help,
Chas