Problem With export from Access

[pser]

I have a query like this:

SELECT [Person].[Personnr], [Person].[Fornavn], [Person].[Etternavn], [Stillingsgruppe].[Navn], [Person].[Ansattdato], [Organisasjon].[Navn], [Person].[LonnsGID], [Person].[AvdID], [Avdeling].[Navn], [Person].[Eksamensaar], [Person].[Merknad]
FROM Stillingsgruppe INNER JOIN (Organisasjon INNER JOIN (Avdeling INNER JOIN Person ON [Avdeling].[AvdID]=[Person].[AvdID]) ON [Organisasjon].[OrgID]=[Person].[Organisasjon]) ON [Stillingsgruppe].[StillingsID]=[Person].[StillingsID]
WHERE IIf([forms]![meny]![chkexport]=True,[Avdeling].[SelskapID]=[Forms]![Meny]![cmbSelskap],[Avdeling].[SelskapID]=True)
ORDER BY [Person].[Etternavn];

My problem is that after i've tried the export a number of times i get error and when i try to open that particular query (above) it's empty, the only thins there is SELECT;

So anyone know why i after a certain amount of time lose query.

Steven