Who said i5 has some problem? Yeah I'm using i3, its great for gaming and cheap at the sametime, but if you have enough cash to go for an i5 then why not? I don't think it has any problems. The first generation Core I Series i5s had no issue, don't know about the second generation processorss. However I'm pretty sure they are problem free, if there was a problem there would have been some news regarding it. Anyways try asking in PC HelpDesk too for confirmation.
Hope this helped.