Item quantities automatically changing

[bowstock]

Sorry if this is a known one - a search did not bring it up.
I have a customer who wants 2 of an item but says he is being forced to add 6 to his cart. I have observed this - I entered '2' but '4' appeared in the add to cart box.
I have compacted the DB and uploaded and all seems OK now. Is this a known issue or am I cracking up?

The site has behaved perfectly up to now.
I am running 7.0.2.0.0.0 ELCA and due to run the 7.0.7 patch in the next few days.

[jont]

Is this happening with all products or just the one instance? May be worth deleting the product and adding it back in again from scratch to see if that resolves.

[bowstock]

It was just the one product and it only seems to have happened once.
Twilight Zone stuff?
I'm not particularly worried but I do enjoy getting to the root of these little glitches.