jihelbi:
Tome Carpenter I don't understand your post...Try it before post unwarranted comment !
I don't think it was unwarrented in anyway. I downloaded your zip file. Uploaded your sketch to an Attiny85 running at 16MHz as specified. The transmitted baud rate even though set to 19200 comes out at 10000baud.
I am not sure about recieving as because the two are at different speeds I cant use a serial program to send a byte and then check the response.
You are correct about the timer interrupts, that shouldn't cause an issue, the 18% figure was a moment of misunderstanding (just a delay of 8uS before the start of the packet). However be that as it may, it doesn't change the fact that the sketch I downloaded from your link doesn't put out the correct baud rate for me.
My post was a question asking what could be causing the problem. Now it turns out it was in fact the fuse setting that was wrong and the clock was running at 8 MHz rather than 16MHz that was causing the issue.
Now for the future, instead of shouting at someone who asks a question about how to fix a problem when using something you wrote, you could try and answer it rather than telling them there post was unwarrented.
Oh and my name is Tom, not Tome.