Could not update; currently locked by another session on this machine

I have been using this form for for the last 2 years - suddenly I star getting this error!

It got to be with the data - I loaded a backup data file from Nov08 and all seems fine

Any Ideas?

What do you mean by "loaded a backup data file"? Do you mean you imported data into your database, or are you using linked tables, and you just relinked those tables to your NOv08 dataset?

re-linked backup data set
front-end stayed the same

You may have a stray lockfile. Locate the dataset you were using when you had the trouble, and see if there is a lockfile hanging around - a lockfile is a file ending in .ldb, and will be named the same as the database with which it is associated, so if I have a db named Scott.mdb, the lockfile would be named Scott.ldb. Delete that file and see if your error goes away. Note that no one can be accessing the database when you try to delete it.

I am the only user
the ldb is correct
The error occurs when a bound form is running closing code
and a sql statement tries to create an edit recordset while bound form is open
Not all records produces the error
and the form has been working for the last year
obviously something has changed with the data
I have looked at before and after records
Success and failure (re:3188 error)
and cannot find an anomaly

This often causes locking errors, depending on what records are locked on the bound form. In general, either update the records in the FORM, or in CODE, but not both.

You might try a Save on your bound forms before attempting to write:

Me.Dirty = False

will force any pending saves to disc.