I installed virtuemart and created a catagorie with some products. This all worked fine, but as expected everything was in englisch.
I then installed the NL (dutch) language pack for joomla (not virtuemart) and installed it, this seems to work as the backend is now dutch. I then downloaded the language pack for virtuemart and unzipped it, I then got a file with a lot of zip files like admin_cs-CZ.zip
i didn't know if this was oke, so to be sure i also unzipped these files so i now have a file with al of the zip files and there unzipped versions, the file/folder is called languages. I uploaded this language file to public_html/administrator/components/com_virtuemart/languages
This is where the trouble starts, when i set the nl language as the default language for joomla the whole shop changes, before the change i had a list of the catagories and a div with the products of this catagorie, but after the change the catagorie list disapears and instead of products it says:
Featured Products
Latest Products
Top ten Products
And as you can see it is still in englisch. The shopping cart does still exist, also in englisch.
I use joomla 2.5.7 and virtuemart 2.0.10
Following your description, it is possible that you started to enter dutch language product descriptions into the english language product database tables. You can check that using phpMyadmin or similar MySQL database tools. If installed correctly, your dutch product descriptions would be in the table ..._virtumart_products_nl_nl.
Here is a multi-language setup description: http://forum.virtuemart.net/index.php?topic=104901.msg349135#msg349135 (http://forum.virtuemart.net/index.php?topic=104901.msg349135#msg349135)
There also is a dutch language installation tutorial somewhere in the internet, but I didn't find the url immediately.