Originally Posted by BigVoxjammer
It's weird there are a variety of seeming causes for this problem, and very few (though still enough) people experiencing it. At the risk of reviving a potentially old but interesting thread, or mentioning what is already common knowledge, I'll add what I read on page 3-4 of the manual, namely that in some situations the key won't start the car if another transponder key is near it, or if a normal metal key is munked up on your key-chain, thereby touching your ignition key, and presumedly grounding it. I jump in just to suggest to those having an intermittent issue that it could even just be this simple thing.
I carry around my Impreza key solo, so unfortunately its not that