Run-Time Error On Form Open

[Tim J]

I am getting run-time error 3008

'The table (TableName) is already open exclusively by
another user, or it is already open through the user
interface and cannot be manipulated programmatically.'

I get this when trying to open the form in code from any
other form that has a record source.

If my current form has no record source then the other
form opens fine.

Any Ideas?

TIA,

TimJ