Boxster stranded me twice this week.

[ScottStu]

Ok, I have done the searches and I think I know what is wrong but would like some help.
I was driving last Wed and she just died. Would not start but would crank well. I don't think the tack moved at all. After a disaster with the road side assistance (three hours later and a dead battery from having the flashers on) I get home and the tow guy helps me jump the car....starts right up.
The next morning I check the battery (Shows it was bought in Jan 2001)and it has 10.2 volts. I jump the car and the alternator shows 14.6 so I have a bad battery.
Today I am driving and it does it again. I'm only three blocks from home so I hoof it and do some searching, it looks like the crankshaft position sensor. After about an hour, I go and get the car. She starts right up...
So my thought is the Crankshaft Position Sensor....am I right.
Oh its a 1998 Boxster with 107000 miles and I have owned it since May of last year.
Thanks for any help.
Scott