We have configured Joomla 1.5.23 with JoomSEF 3.9.7 with K2 extension 2.0.10 and SEFs are working OK except for any item that has a second category. We are using another component for K2 called K2 Multi Category usjoomlapros.com/forum/K2-Multi-Categories to allow more than one category per item.
The URL defaults to a non-sef link.
This means that most of our URLs are not SEF.
Please suggest a solution.

Hi,
Thank you for your report. The K2 Multi Categories is not currently supported. Because the component is commercial, we'll need to ask its developers for a development license, so it will probably take some time until we obtain it and test it.
In the meantime, could you post an example of non-SEF URL generated by the component? Thank you.

This page contains many examples:
www.realbuilders.com.au/projects/project...s/complete-new-homes

We trust that commercial products deserve support. That's why we purchase and support the developers.
The issue also is affecting a module we have on the home page links for featured K2 items - Latest Real Builders Projects.
The (Itemid=1) is appended to the URL on the homepage when it is not required.
e.g. www.realbuilders.com.au/index.php?option...p;id=42&Itemid=1

We just resolved the isssue with the K2 module link on the homepage.
Changed the setting in advanced configuration under Itemid handling
Set Exclude source info (Itemid) to Yes.

However, the problem with multi category extension remains.

Hi,
I've just contacted US Joomla Pros and I'm waiting for their feedback. Please be patient.