Canon T3 vs Canon T3i?

I'm looking for an introductory DSLR camera. A lot of these are really nice. Was looking into the Nikon D3100 however, heard a lot about a glitch with ISO settings causing pictures to come out grainy. I found the Canon T3 and seems to be what I'm looking for, however people complained that the photo quality wasn't as good as on the T3i. As I said, I'm a novice, would mostly be using this for vacations, special occasions, some every day, etc. If I do prints they're going to be 4x6 or a bit larger. Would you recommend that I went with either of these, and why?

Glitch? All cameras produce grainy pictures when you use high ISO values. It has been the case even during the film era.

Any dSLR will do. They are all basically the same. I highly recommend you get more than the cheapest model for more shooting pleasure. The cheapest are crippled in one way or another.