Can anybody answer this:

If you open a table in a form's data environment and the table is already open, which copy of the table is used?

We seem to have a problem with buffering here (all forms are default data session - horrifying, but that's how the app was designed!). The form's data environment opens table 'x' with BufferModeOverride of 1 (use form default). Form BufferMode=0 (no buffering). I have put a trap in the form (save button) to kill the process if buffering is on. This trap has been hit!

Buffering is set to 5 for table 'x'!!! I have discovered a previously visited form has CursorSetProp of 5 for table 'x' but it also has autoclose .T. in it's data environment.

Let's say the table was opened earlier in operations. Does the data environment override existing open tables??? Or CAN IT???