Hi Manno,
The ACT importer shipped with Maximizer is not perfect! We have developed our own in house ACT importer which retains your Groups and de-duplicates your data (ACT databases frequently have duplicates due to the way companies are stored in the database)
If you wish us to quote to convert your data then please send a sample to support@cabc.co.uk and we will be happy to give you a fixed price quotation.
Regards
CABC Support