Nah. "Cogito, ergo sum" is obviously wrong if we think about it for even a moment. It's a thought terminating tautology at best.

A) Just because there is thinking it does not follow that there is an "I" doing it.

B) Perceiving something does not in and of itself prove that either the thing or the perciever are "real". Some things are real without being perceived, and some things are perceived that aren't real.

C) Even if we grant the reality of the "I", What is the thing that is perceiving the "I" which is doing the thinking? We cant trust something that may be a faulty instrument to report on its own actions.So we can't actually be sure that we are thinking and not just falsly remembering that we once thought. See rootkits for an example. If we're starting from first principles (as Descartes intended) we immediately fail because we require an outside observer.

D)Etc.

Basically every major philosopher since Desacrtes has already had a go at this one. I'm sure there are better arguments against it out there already. These are just the few that spring to mind.

Really, its just the place where Descartes gave up, not a universal truth of some sort.