Tulips are terribly variable - some come up year after year and flower, others only produce a few leaves, or don't show at all. I'd be inclined to replant the ones you have, but also buy some new ones, and see what happens with the older ones. The only drawback is you have to remember where they're planted!

Many times the smaller bulbs just give you a bunch of leaves and no flowers or nothing. I'd plant all new ones for the planned location.

Were these bulbs from a pot of forced bulbs bought while blooming? When tulip bulbs are planted shallowly, as in a forcing pan, the bulbs break up into many small bulbs that will have to be planted deep and grow leaves for several years before they will bloom again. Not sure why this is, but it seems to help them survive landslides in their native Asia Minor mountains.

Tulips, like most bulbs, have contractile roots so that they can position themselves at the correct depth in the ground if they have been planted to shallowly. In a pot they can't do this and you end up with a lot of smaller bulbs. I'd find somewhere out of the way to plant them and let them get on with it for a few years then they'll start flowering again :)

Thanks everyone. I'll buy new ones and replant the old ones somewhere else.
Tug, no I planted them myself in a very large pot.

Moongrower - how interesting, that's something I didn't know... thanks.

You're welcome Bamboo...