Lastly, are you always pasting the first five-ten pages of your novel after the query? I usually did that even if the agent said they didn't want a sample, because they can choose to read it or not.
You have had success with this approach, TereLiz? Just curious, as I have been too scared to send anything the agent didn't specifically ask for, as they all seem so particular about their submission guidelines. The agents didn't seem off-put by your extra content?
(Eleven form rejections and one full request for me so far, so I'm not sure what I'm doing wrong or right at this point.)

Eh, I usually included it anyway if the agent seemed pretty laid back about their subs. I know it's one of those things where you don't want to break the rules, but I figure it's not wasting anyone's time if they don't want to read it. And that way a sample is there if they want to read it.
I just checked to see that I did get two full requests from agents whose sub requirements said not to send pages, and one wound as my agent (eventually). That said, I'm not an agent, and if a particular agent seems to be a real stickler for people following their rules (sources like blogs and twitter streams can be helpful here), you should do whatever you feel presents you in the best light.