Taxonomy terms are untranslated in Catalog block

verbatim from http://www.firewing1.com/node/27

This one had me puzzled for a long time. At first, I had enabled localized terms for the Catalog vocabulary. After I created some terms, I translated them using the Translate Interface tool as usual, but this did not work. Editing a product would show the localized term in the Catalog list, however viewing the product always resulted in the untranslated term being displayed on the Catalog block. The solution is to navigate to Administer > Content management > Taxonomy and edit the Catalog vocabulary, choosing Per language terms. Use the following procedure to define taxonomy term translations:

1. Browse to Administer > Content management > Taxonomy
2. Add a new term with its translations:
1. Add a new term to the Catalog vocabulary in the default language of your store and choose that language from the drop-down menu
2. Repeat the above step, but enter the desired translated texts for the term (including a translated term name)
3. Repeat the above step, but enter the desired translated texts for the term (including a translated term name)
3. Click on the Translation tab of the taxonomy interface
4. Click Create new translation and pair up the original term with its translations
5. Repeat the step above for each term that you created earlier.

[This is why] you do not want to synchronize taxonomy terms, with this setup each term is translated the same way nodes are - separate terms per node, linked together with some metadata. Synchronizing taxonomy terms would result in your products appearing in the right categories but in the wrong languages!