Who_Am_I wrote:
I've just read it. I agree with most of it, but one part I don't agree with is that when someone says "I don't know" in response to one of your problems, that this means they don't care about you. They may genuinely have no idea. They may need more time to think about the problem, and "I don't know" could be a way of buying some time. I'd rather have someone admit that they don't know what to do about my problem than to give me bad advice, or, even worse, lie to me because they feel pressured into trying to solve my problems.
i agree. you can't put definite connotations to "i don't know".
i use it all the time, not because i don't care. but sometimes because i
honestly don't know 
or just don't know how i should answer

I know what you mean, but i've had "friends" that have said "I don't know" before. I look back now and realize that they really weren't my friends because they told me off one time when I was at a party they invited me to. I have never talked to these people since.