Hey! I solved this problem! The trouble was that my old motherboard is too "stupid" to be able to read the chips of 32 mb size (the stick was 256 Mb with 8 chips on it). So I changed this stick to another 256 Mb dual sided stick with 16 chips. Now it works perfect (I also installed it in right order). The only trouble, that I should add 40$ to change 8-chip stick to 16-chip one.
But now I have 256+128+64=448 Mb of SDRAM!!!
This RAM upgrade was the last one in my upgrade program, so now I can proudly post my system spetifications in my signature!
Even my comp is still the old one, but after all upgrades (video card, CPU overclock, hard drive, memory) it works pretty good.