At first thanks for your efforts aus9.
I've solved this problem but I still think that default GRUB installation method worsks at least 'STRANGE' - even if it will do the job for most setups. I want to distinguish two installation cases (stage1 and stage2 locations are specific to my setup):
1. setup(hd3,1) or
install /grub/stage1 (hd3,1) /grub/stage2
2. install /grub/stage1 d (hd3,1) /grub/stage2
So, variant 2 works fine while variants 1 just displays "GRUB _". I'm almost sure that debian 5.0 setup uses variant 1, while centos 5.2 uses variant 2.
All documentation sources on WWW sugests setup command as proper instalation method. Now about 'd' option, form standard documentation:
If the option d is present, the Stage 1 will always look for the actual disk stage2_file was installed on, rather than using the booting drive.
So if target drive is not 'booting'(that is my case) the default way is not to look stage2 where I installed it ! It's realy stange that this behaviour is default (setup command).