Why do I have to burn the bootloader to my UNO r3 so often?

Yes!
that helped me with 0 in numbers :slight_smile: Thank you

As for now I load corrected sketches and it is still working fine
I don't know what was the problem earlier... maybe my USBasp didn't burn the loader properly?

I have (cheaper) STK500 and AVRisp mkII compatible programmers but they don't wan't to work with IDE