Hello,
I saw this hack forum.virtuemart.net/index.php?topic=57831.0 and I applyed the files correctly. This time i'm getting the next problem:
- when clicking a category I get url like www.scompro.ru/shop/optovolokonnie-mikroskopi-huxscope
- when choose the manufacturer from combo-box I get url like www.scompro.ru/index.php?manufacturer_id...word1=&keyword2=

Joomla 1.5.14, VM 1.1.3 + Filter products by manufacturer, JoomSEF v3.3.6, VM extension 2.0.6

Please help me to solve this problem.

It seems the link to manufacturer is not processed by JRoute function and thus it is not SEF. There may be also missing some important variables such as option, page, etc.
Please, make sure the URL is in full VM format and is processed via JRoute function.

The URL is in full VM format looks like "index.php?orderby=product_name&DescOrderBy=ASC&Itemid=2&option=com_virtuemart&page=shop.browse&category_id=&manufacturer_id=4&keyword=&keyword1=&keyword2=&limit=/scompro/shop/plantronics-2%3Flimit%3D5%26limitstart%3D0&limitstart=0"
Does the extension support all features of this format?

Hello,

yes, the URL format should be correct. However, the important issue is the fact mentioned above - whether the link, before it is generated in the HTML source code, is parsed via the JRoute function.
If not, then it is not processed by SEO engine at all and stays untouched.