Last month I noted that a system that has been running without a hiccup since 2001 had a corrupted index that had the effect of making a report view OK but print incorrectly.

I reindexed and packed the table last month and all was OK

Same call today (this is a monthly process).
This time reindexing and packing didn't work.

I brought the data to my system and failed the same way the user failed.
I reindexed and packed and all was OK on my system.
Hmmm
After several futile retries at the client, I sent my corrected .dbf and .cdx to the client and all is OK.

Que pasa?