Database Pager for a new entity type I have implemented a new entity type that requires paged access to DB and meet a probem with several pagers for independent entities on the same theme page. 

The problem is that that entity can be used along with the node, thus two (or more) pagers may co-exist on the same page. The element property of PagerDefault apparently does not work (see discussion). In addition, PagerDefault simply uses $_GET['page']) to find required page number, which leads to even bigger confusion - both absolutely independed DB queries share same HTTP page query parameter.

What do you believe is good solution of this problem?  

Further investigations have revealed a bug with EntityFieldQuery::pager()
I'm not sure I understand your problem ... Are we talking about like a node/edit page or a View? Or is this a menu page callback where you want node(s) and this entity both with paged output on a single html page ... ?

If you have written custom PHP/SQL/EFQ in a menu page callback, I see no reason you cannot explicitly set $element uniquely as needed in your queries.

Where is your http page query parameter coming from? A view? A url() you created by hand? If you have 2 pagers, you should have 2 $GET parameters ...

Edit: this is what I mean blog example