Battery Not Charging... Any ideas?

[TheKoP]

Hello all!

I've been having a bit of an issue recently. It started back in November, when my car just wouldn't start. Checked the battery, found it to be fully discharged and since it was the one that was in the car when I bought it (april 2006) I just decided to get a new one since I wasn't sure of the age. About a month later, my car wouldn't start again. Same problem. Recharged the battery and things have been going fine until yesterday when the same thing happened.
Now, I've checked the charging system and it seems OK (Checked myself and had my friend's garage do it also). I was thinking there might be something that is drawing current when the car is off but I've yet to find anything. All wires and connections are good. Also, the car is driven daily for a decent distance (at least 15 miles to work) so it's not like it just sits for weeks and won't start.
I'm hoping someone here has had similar charging "gremlins" and has found a solution. Any suggestions are welcome as I'd like to avoid being stranded a 4th time. Thanks in advance for any help!