I have the same problem as desribed here -
http://forums.opengoo.org/index.php?topic=3414.msg12726#msg12726!!
I did everything like in your description, first export companies from opengoo then import with changed data, but error 500 is coming up instead of importing companies.
Is there a fast fix possible? Since today after upgrading from 1.6beta2 to final 1.6 i need to import the companies and now it does not work:-(
Greetings Claudio