Breadcrumbs and 2nd menu level random inaccuracies

-- url of the page with the problem -- : www.intera.ee
-- HikaShop version -- : 2.1.0
-- Joomla version -- : 2.5.17
-- PHP version -- : 5.2.x
-- Browser(s) name and version -- : tested with Chrome and various versions of IE

I'm running Hikashop to display a range of products divided to categories and subcategories and thus the product menu has two levels.
The problem starts when i click on a main category and the 2nd level of category links is displayed: a random 2nd level link is highlighted.
Example: http://www.intera.ee/index.php/pehme-moobel where when i click on "Pehme mööbel" menu link the subcategory expands and the menu link "Voodid" is highlighted. Similar random menu link highlight appears for every second level category on the site. What causes it and how is it fixable?

Also, it would appear that the breadcrumbs have two different inconsistencies:
1. depending on whether i click on subcategory menu link or pictogram on the site, it either displays or doesn't display the subcategory in the breadcrumb.
2. when i follow a link from a product page to an associated product page or the the manufacturer page the breadcrumb does not update. I did read that the breadcrumb only displays the pathway, not the actual location of the displayed hikashop content, but is there a workaround to this to make the breadcrumb functional again?