thanks Dave...
Yes I did try restarting TivoWeb, but late last night I found another solution. I manually loaded the slice data and all seems fine now. I guess my data became corrupted somehow (it is still only a week old machine for me, and I'm climbing the learning curve).
After manually loading the slice files and indexing I have the grid back (although I note this morning that the "LifeStyle" channel has no guide info)....

cheers,
Wayne