Yes, I get the reply. They sent me the same datasheet and schematics that I have already had - nothing new. But maybe I find out where the problem is... The schematic that is suggested by realtek uses 20F001N

http://www.uhf-satcom.com/misc/10MH...0F001N.pdf

that contains low pass filters that have been specifically designed to implement the functionality of analog interface for 10BaseT Ethernet application. RTL8019AS is only 10BaseT. MagJack does not contain these filters because it is designed for 10/100BaseT and that is why it does not work, I think. So resolutin is to use this module (20F001N) or use Magjack and place low pass filters between Realtek and Magjack. But it is very difficult for me because I have no experience with that...