Bizarre behavior

I have a bizarre problem, something I've not experienced in all my years with Arduino.

I have an old, stable project that uses the TVout library. When I compile and upload it via my Windows7 installation using any version of the IDE it doesn't behave properly. The compile and upload completes fine, but something is botched with the compiled code because it crashes on the Arduino soon after, losing composite signal, etc. If I copy the exact arduino IDE directory (with libraries etc) and project directory to an XP virtual machine it compiles and uploads fine, and the compiled code behaves as expected on the device.

On the Windows7 system I've verified that there is nothing in the system PATH to conflict with (PATH was set to empty), I've removed all other Arduino IDE versions, removed all other copies of WinAVR, deleted all Arduino preferences files and directories, scoured the system registry for offending entries, yet this issue persists. This Windows7 installation used to be my main Arduino development platform so I'm wondering what could have changed to affect the IDE.

Does anyone have experience with this kind of behavior? If so, what can be done to get around it? This is a first for me. Thanks in advance.


Things I've tried since posting:

  • Uninstalling the programmer driver (adafruit usbtinyisp 2.0), rebooting, reinstalling driver. No change

  • Uninstalling the libusb driver, rebooting, reinstalling driver. No change

  • Confirmed via MD5 hash that both .hex files produced on the w7 and XP systems are identical. This singles out the programmer interface or drivers. Will see what dependencies these drivers use and update soon.

It wasn't a dependency, now I have it down to a USB port. If I switch the programmer to a different port the code uploads properly every time and the code behaves as expected. Dumbfounding.

If you have another Windows 7 PC, and who doesn't who is a geek :slight_smile: , I would try to compile the sketch on that PC.