Mac OSX 10.9.1
AVR Plugin: 2.4.1
AVRDude: 6.0.1 (CrossPack-AVR-20131216)
AVR ISP: Dragon and MKII
trying to upload a hex file to an AVR while the ISP is disconnected or while the target is not powered (or something is wrong in general) may cause the USB stack of my MAC to blow up (reset). Changes are about 30-50%. When it blows, my mouse, keyboard, and everything else stops to work for approximately 2sec. After that all works as previously except the AVR ISPs. I need to reboot in order to get them recognized by the system again!!
I tested it on two machines using two (USB) programmers. I always had the same result...
This problem is definitely related to avrdude and/or libusb. However I cannot reproduce this issue in the terminal as the timing seems to be critial.
For workaround I wrote a script (attached) for delaying the individual avrdude invocations by 250ms. This seems to do the trick for me.
It would be nice if you could include this small delay in the next version of your plugin.