Ignition problems
 

I have a strange problem on my 2004 Legacy 2.0i saloon. When I use the car first thing in the day it always starts first time without any problems. However, when I use the car later in the day, more often than not, it doesn't start. I unlock the car as usual, put the key in the ignition and turn it, but nothing happens. There is still no response even when I hold down the button on the fob. Usually, I then have to go through a sequence of locking/unlocking the car before it eventually starts.

There seems to be no pattern to this as sometimes it works normally, but other times I leave it for 10 mins and it doesn't respond when I try to start it. Other times when I park it at work, it will start first time when I return to it after 9 hours, or sometimes it won't. I've tried leaving the car unlocked, but it doesn't really make any difference. I also tried a different car, but it doesn't make any difference either.

The problem seemed to start soon after I had a headlamp bulb changed at a Subaru dealer, but I think this is probably coincidental.

Aside from this the car runs perfectly, but it's becoming very frustrating.

I'd be grateful if any has any suggestions, or has experienced a similar problem with their Subaru.