Yes, very important. Two pins driving opposite logic outputs (or even same logic 1 output at different voltages sometimes), is often a good way to get 'the smell' (in my experience with other electronics), and can also make chips behave oddly as a side effect, such as spurious data glitches.

I'll add: Sometimes it's important to set particular GPIOs in a particular way (direction, value, maybe other options) early in the boot (though I'd expect the bootloader to do that - maybe the later kernel is changing them wrongly), and similarly some I2C devices may need setting in a particular way early.

So to lay out out clear, here's the suggestions so far:

• Need to trigger power saving mode (speed, voltage) at the right times to limit heat output (hint: lock to low values for safety at first)
• Voltage set too high in PMIC
• Muxed pins set incorrectly
• GPIOs / I2C registers set inappropriately for the device

I'm really pleased someone's trying to bring the kernel up to date. 2.6.40, bring it on