Can Apple tell if ive jailbroken after ive restored?

[swederland2002]

I have 2 iphones, both jailbroken, but i need to take one of them in cause the home, sleep/wake and volume rockers are not responding very well. i restored it back and updated it to 2.2. I only jailbroke it, never unlocked it since i don't plan on leaving AT&T. My question is will Apple be able to tell that ive jailbroken my phone even after ive restored it? Has anyone ever restored their phone after a jailbreak and then taken it to Apple for warranty care? please let me know ASAP. Thanks.