hmm.. well the sitemap i generated with xmap and I have not changed the k2 structure or so.. this is really annoying and it seems to change from time to time..

It could be working in one day and the next I have /k2/... :/

Open the K2 extension parameters using the Manage Extensions page in JoomSEF and on the Common tab make sure that "Handling" is set to "JoomSEF handler".
If the /k2/ appears again, check if they are present in JoomSEF's URLs Manager and post some examples of them with the corresponding Real URLs.

Best regards,
ARTIO Support Team

I've got the same issue: some items from the same category have /k2/ prefix, some menu title.

For example:
Item1: /k2/category/subcategory/item1
Item2: /menu/category/subcategory/item2

As suggested handling is set to JoomSEF handler.

You may take a look at sitemap here: vdvkiev.com.ua/index.php?option=com_xmap...temap=1&view=xml

Real URL with /k2 prefix: vdvkiev.com.ua/index.php?option=com_k2&a...=item&Itemid=187