Random Shutdowns on a MBP Core Duo, Suggestions/Help would be great

Question

I've had two random shutdowns of my mac since purchasing it back in August. The first happened on January 11th, when it said it was at 11-12% power. The second happened about two weeks later, at 23% power. I've been looking around these forums and other pages, and haven't really found anything that has helped so far.
Details of the first crash:
Open apps- Firefox (5 windows, two had about 20+ tabs open, the rest were single page, and yes, I know it crashes often with that many), Camino (1 window with 5 tabs), and Word 2004, as well as Quicktime open to the iPhone stream.
I had an USB key plugged in, to which I was saving my Word document.
So I was working in Word while in front of the TV and during an interesting bit, didn't do anything for a minute. So, like the many times earlier, it slept the display to conserve power (in "Better Energy Savings" mode). I moved my finger on the trackpad to wake it back up, and it turned back on the backlighting, and then stopped. I thought it had just went back to sleep, but after a few key presses and a check of the light that usually pulsates when it's sleeping (plus the USB key , I found out that the computer had turned off. I let it sit for a while, and when I plugged it back into AC power and turned it on, with my USB key still plugged in, and although it booted to my desktop, the Finder never started (so no desktop icons for anything), unplugging the USB key fixed this and everything returned to normal. I then installed the only update I was missing, one for iChat, restarted, and continued working.
In the second incident, I only had my browsers open, nothing external plugged in, and my displayed was dimmed to the third darkest level. When it was at about 23% power, it once again randomly shut down. This time, I attempted to turn it back on, and nothing happened. After plugging it into AC power, it turned on and once logged in showed a very low (2-6%) power, so I guess it was reporting the power incorrectly?
Anyways, went back to look at the battery exchange on Apple's website. I had checked before when they started it, and was pretty sure mine wasn't covered, and a second check confirmed that. My Mac's serial is W8618091VWX, which isn't covered by the recall.
So, I have a few questions:
1. Is there a toll-free number I can phone Apple (Canada) at? The only number I've found seems to be only free for those who bought their computer in the last 90 days, which I'm no longer covered by, and haven't been for a while. Talking to someone at Apple would be good.
2. Otherwise, if I took my computer to an Authorized Service Provider, would they be able to take a look at it and answer some questions? I bought my MBP at a London Drugs and they aren't service providers, so how much would it cost to do this?
3. Is there a definite cause for these random shutdowns? It seems to vary among other people, so it would be helpful if I could try something to eliminate one of the causes.
4. Does Tiger report battery levels pretty accurately? In the past when I reached 6% I got a warning and was able to plug it into AC power and had no problems.
Thanks for any help you can provide.
Macbook Pro 2.16 GHZ Core Duo, 15.4", 1GB RAM   Mac OS X (10.4.8)  

Answer 1

I had this problem of RSD fixed for a while after having had the battery replaced by Apple, till yesterday, when the MBP suddenly experienced a shutdown during a meeting presentation, while it was connected to the AC power. At the first restart, as coming back from a stop-mode, for a while appeared a warning of low-battery level, with battery level indicator flashing red and showing the empty icon but with a 86% of charge level and a new shut-down definitely put the MBP out of service, no way to have it functioning again. Obviously, AC power was OK, no problem with the microphone or the projector ( I was at the podium of an international meeting) and a lucky precaution ( double save of the same presentation on a friend's twin MBP, that worked correctly) saved the job.
Then, a couple of hour later, my MBP started up normally and everything works fine, with or without MAGsafe connected to AC power, almost up to now.
I've read the post with a link to the procedure for resetting the power controller chip on the mainboard, I'll do it in a minute, hoping that this will help.
Any further suggestion?
ambabu, Italy