Thanks. I'll try that when I get home. What I don't understand is, as I mentioned above, if I measure the resistance of the resistor when it is in the circuit and the circuit is active, the voltmeter gives me values of 0. When I measure the resistance of other resistors in the circuit, I get the correct values, regardless of whether the circuit is on or not. That's what I find weird.
Anyway, that's an aside. Just thought that commenting on that would help diagnose the problem of why the led won't stop blinking after 20-30 seconds (ever, in fact), once I've pressed the button. I was hoping to get to the bottom of this!
