[3.5] Question on infusions and spells

[ErrantX]

So, I'm curious as to what the actual rule is on this:

So if I'm playing an artificer or sorcerer (or really any prep caster who wants to) use a higher level slot to cast a lower level spell / infusion (or for the prep caster memorizing a lower level spell in a higher level slot) is that good by the rules?

The reason I ask is because in the past, with Sorcs, Clerics and Wizards, it hasn't been a problem. With Artificers however, it seems that every infusion slot becomes a Spell Storing Item when my player has the time to do it. So... what's the actual rule on this? Can a caster of any variety use a higher level slot to cast a lower level spell without use of a feat or anything?

-X

[Chronos]

Yes, but you don't gain any benefit from doing so, other than getting more uses of your low-level spell.

[ErrantX]

Cool, that's what I wanted to know.

I was pretty sure this was the case, but I wanted to make sure all the same.

Thanks!
-X