Well I thought I'd put your mind at rest. Last autumn my little girls were given a packet of tulips (praestans 'Fusilier', in case you're interested) and we had a lovely muddy session in which they enthusiastically planted them all in their little gardens outside the wendy house. I did tell them which way up to put them, but, well, when you're seven you get a bit carried away sometimes.
So - I was weeding that bit the other day and accidentally dug up one of the tulip bulbs (a bit of an occupational hazard at this time of year I find). And this is what I found.
Now, doesn't that make you feel better? No matter which way up you plant a bulb, it seems, it manages to sort itself out perfectly well, thank you very much. So next autumn, sling 'em in and as long as they're not waterlogged or pulled up by squirrels, things will turn out just fine.
I re-planted this one right away. Upside down, of course: it seems to like it that way.