Dear Alan Richey, 
I have tested your custom bin file for MOD303 with my Slingbox Solo. It works fine except it has the infamous double click problem where one press of a button registers twice. So 1 becomes 11, 2 becomes 22, <- becomes <- <-. 
The power button works fine. 
I have read lots and done a bit of research across many forums and have come to discover that you're an expert who very actively help out the the Slingbox community. I want to, on behalf of the Slingbox community and myself, acknowledge and thank you so much for all your kind help. You ROCK! 
Now regarding the double click issue, I came across this thread 
http://answers.slingbox.com/message/35015#35015 
where you were able to fix an identical problem for someone else. But here
http://answers.slingbox.com/message/58032#58032
the person wasn't so lucky. So it seems whether the problem is repairable depends on the device and the IR protocol. 
Are you able to disable the repeat protocol for MOD303 also? Thank you again for everything. 
Cheers, 
Allen