Recently found something usefull. I don't know how does it work exactly, but anyway:
- Make second material, which will be replicating first Transparent material in all aspects except for transparency (!).
- Then enable nodes and plug Transparent material to the Output.
- Finally add another Material node (Input-> add Material node). And choose there your second material (one without transparency), but don't plug it anywhere, just click it with RMB to set as active in node system.
P.S. It is not the best solution and I guess, it can corrupt other passes with more complex materials.