Got my N96 a week ago. This is what I have noticed so far. When I activate the "power saving" which you can by pressing the power key half way located on top of the right hand side of the phone. Then scroll down to "power saving" & activate it.
I activated the power saving & after a while when I want to make a call or open the slider & the phone does not respond.
To solve this problem I have to remove the battery, reinsert it again & turn on the phone again.
This issue does not arise if the "power saving" function is not activated.
Apart from this, I have no complains so far. I had used the N95 & N95 8GB before & I find that in terms of size & looks the N96 is a winner in every front.
Will post again on other aspects of it.

There's a v11 firmware available for the N96. Try see if it helps.

Yes, the software update did resolve this for me.
You can find info here: http://workshop.nseries.com/

Thanks for the suggestions guys.
Only today I have also experienced phone shutting down by itself. When I start to switch on the phone again, the phone does not respond at all & it was just like the "power save" issue haunting me again. I had to literally removed the battery, reinsert it back switch on the phone & it responded. Battery was still full.
Never experience any crashing so far & I am keeping my finger cross but then again I am not a heavy user.

Just installed the updated software version 11.018. The original version is 10.065.
So far so good as all the problems I have encountered prior to installation of software version 11.018 seem to have disappeared.