Can't replicate this problem: Seems to work AOK using channel 1 or 3 with or without the interrupt.
This was on a 'clean' build - I use a new directory for every file - I wonder if you've changed any settings in menuconfig that are 'upsetting' the output (attempting to output something at a different baud rate??)
Do you have BT enabled?
Even so - having an empty timer interrupt seems an unlikely fix?
Try using the batch file from the last post of viewtopic.php?t=2966&hilit=batch+file+e ... uild+speed - this gives a 'fresh' configuration for each project - just note you need to use compile to hex and set the com port in the batch file - however I use it for all eps32 projects - it it works well...
