Form not returning after code execution

[JM]

We have a Access db that takes some tables and generates a fact table for an
OLAP cube, which is output to a text file. The fact table has about 6-7
million rows and is composed of 3 tables. The VBA code works fine albeit it
takes 3 hours to generate the output file.

This would all be fine except that when execution is complete the Access
form (or the db) does not respond to user interaction. ie the final event is
MsgBox "Done" which does not respond to the OK button being click by the
mouse. I have checked the VBA code to make sure the objects, particularly
recordsets are closed and released and they all are. I have added code to
repaint the form after completion but it makes no difference.

Any suggestions

 

[JM]

Additionally I should point out that the Results file is 568Mb big. Also
when I ran this in the development stage with dummy data the result table
was about 500,000 rows and presented no problems at all.