Heatsink a little on the loose side - problem?

[SantiClaws]

I have one of those heatsink/fan combos that attaches via a clamp (Zalman CNPS9500). It is not dangling, but I can twist it with my hand back and forth easily, which I'm not used to - usually the heatsink is clamped down hard and absolutely immobile. At stock the temps on my 2500k is in the mid 60's so no issues, but I do plan to OC. Is the slightly looser than normal HSF going to be a problem temperature wise? I did not notice the plastic heatsink frame being attached loosely to the mobo, but didn't check carefully - could that be the cause of the problem?