Start/Stop problem...help?

Hey guys, my Infiniti i30 has a problem.

Sometimes it will start. Sometimes it will not start. There is no middle ground. The dashboard still lights up when the key is turned.

I brought it in to two different places and they are both stumped. Its a new battery installed by mechanic.
Everyone I know is stumped as well. Im sure someone here may have an idea I can look into.

Thanks in advance!

Cavufarm (hope to be a proud infiniti owner)

- Starter or starter circuit bad - test/start by shorting solenoid supply to +12V, see page 5&10 for possibilities, link below
- inhibit relay stuck or one of its inputs on: M/T clutch or A/T selector sw, alarm 'on'