Can underclocking memory cause a problem?

[Guest]

Memory: G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) x2 for 16 MB

Motherboard: Intel DH67CL

CPU: Intel I5-2500

With this setup the BIOS downclocks the RAM to 1333 MHz. My motherboard died during a BIOS flash and Intel tech support claims that my memory "is not designed for 1333 MHz" since it's 1866 MHz memory. And this can cause instability and damage, they claim. They said if there's no SPD setting on the memory for 1333 MHz then "it's not designed for 1333 MHz operation". He claimed that "a memory designed to run at 1866MHz at 1.5v will require less voltage to run at 1333MHz. the latency will vary also. Having too much voltage for the frequency will cause data loss. "

I've never heard of such a thing, that running memory slower than its design point can be a problem because "it has too much voltage for the frequency".

Intel tech support finally grudgingly gave me an RMA after a long chat session. But I'd like to understand if I am actually doing something wrong (which I don't believe) or this Intel support guy is spouting nonsense. More evidence is that this system (and another identical one) have been running fine for me.

I am by no means an expert here so please fire away with advice, if I'm totally wrong that's fine. Thanks.

[Tradesman]

Even DRAM rated for 2133 often has an SPD setting for 1333, most mobo more than a year or so old default to to a 1333 boot setting (1600 is becoming the norm for Intel mobos). Check your sticks under CPU-Z with the SPD tab, I have the Sniper 1866 sticks in my P67 and they have a setting down to I believe 1244. Might ask him why 1.5 is the de-facto standard for DDR3, any decent mobo will allow you to underclock the DRAM and even it's voltage. Intel brand mobos are very tight, and not ones I'd recommend to anyone, they offer very little leeway in anything, to me sounds like you got a person that doesn't know what he's talking about or maybe they even get a little extra for talking people out of RMAs.