DoudouLinux CD

Have you tried a second time? It seems there are sometimes synchronization issues and the video card is not correctly detected.

Yes, I tried several times.
Video mode number is 311 and I selected none,6 and 9 modes - all resulted in blue screen.
My video card is radeon x600

Is it a recent video card? It may happen that it is not detected if it is too recent.

There is a way to generate a hardware report from the command line but you need to manually mount an USB key to save the report and send it. Have you ever mounted a device using the “mount” command?

It's not a recent video card. It's gigabyte radeon

Are you sure of the hardware report you've sent? Both are reporting an Intel video chipset. However it seems the first configuration is correctly working, video should be ok. On the contrary the second seems to be failing but it is not Gondwana, it is 2011-02 (it is written in the first lines of the report).

The 1st PC have video onboard but use another video card which is Gigabyte Radeon

Ok, I think DDL is using the internal chipset. Have you tried to plug your monitor in the internal video card?

Yes, I tried and it makes no difference

English version is started without any problems at the both PC's

There should not be any valid reason for the English CD to correctly set video parameters while the Russian version would not. Are you trying with a LiveCD? If true, the most likely hypothesis is that your CD is not correctly burnt/read.