[cflsystems]

Export products from 4.3.x. Manually create one product in 4.4.x. Export products from 4.4.x. Open both files in excel as csv and make the 4.3.x exported file to have the same format (fields) as the 4.4.x file. Save 4.3.x file as csv and import in 4.4.x. You don't need to import some fields like "date" for example. Also make sure you have all manufacturers and categories already created in 4.4.x otherwise the import will fail.
One of the reasons to use the upgrade script 4.3.2->4.4.0 which will upgrdae the db to 4.4.0, then you can upgrade to 4.4.1 and use the upgraded db