In my template the xmap give me HTTP 500

[Gyuszka24]

Hello,
My site is www.opelcmobil.hu
Joomla 1.5
Xmap 1.2.14
I have two templates. One of them we made use the beez template as basic.
If I set my template as default, the HTML sitemap doesn't work and the Google say about the XML sitemap "General HTTP error: 404 not found".
If I changed the default template to the other one the problem is solved.

Where can I find the reason of problem?

Thx, Gyula