GMAT scores older than 3 years - unacceptable?

Now we all know that according to the GMAC, a test taker's GMAT scores remain valid for 5 years from the date of the test? I recently heard someone from Manhattan GMAT make the claim that there were some schools that did not accept GMAT scores older than 3 years. MGMAT usually knows what they're talking about, but in this case I couldn't get them to name the schools that actually did this.

I've tried to look more into this but haven't come up with a reliable answer. Does anyone here know more about this? Or have first-hand experience of an adcom requesting a retake of a GMAT taken more than 3 years ago?

My MBA plans have been put on the backburner for a series of financial and personal reasons, but I like to map out worst case scenarios (!) and would love to get an authoritative answer on this.

Thanks.