Charlie, it is just not possible to plant daffodils 'too deep' in a tub. They like deep planting. Some daffodils are just earlier than others so, with patience, you will have a progression of early to later flowers.

Phew! Thank you so much Bulbaholic. I stored all the hyacinth, narcissus and daffodil bulbs which I had been given last year and which were in tubs as we are still rescuing our garden from the semi-concreted jungle it had become due to 15 years of neglect before we moved in. I stored them as per Pippa Greenwood's advice, until the Autumn. The Hyacinth bulbs are showing thro', as are the Narcissi but thought I'd screwed up the others - so I'm very glad to read you can't plant the daffodils too deep! I also put some crocus bulbs under some of our newly laid turf; some of them - the golden ones - made it through the turf no problem, but I've had to dig up the purple ones which must be less robust perhaps... Learning a lot, that's for sure!
Thanks again for the reassurance, Charlie