Now I compiled sketch and run program. I have 19200 bps serial speed definition in sketch, but real speed is only 2400 bps.
I tested it still. My arduino with Atmega8 have clock divided by 10 :-(
I selected arduino with Mega8 and internal RC oscillator.
When I make delay(1000); - its take about 10 seconds...
Sounds like you have the fuse setting for a /8 of the clock frequency. The IDE does not factor that in and it thinks the clock speed is the atmega8noxtal.build.f_cpu=8000000L value you stated in your board entry. So either change the f_cpu value to 1000000L or change the fuse setting to remove that clock /8 setting.
19200 baudrate divided by 8 = 2400 baud.