What's going wrong with my cakes today??

[sillytart]

I am making some cakes for a school coffee morning tomorrow, I am usually fine with cakes but for some reason they are not going right tonight

I am making little cakes and although they look fine (in the case) and taste fine
when I peel the case away the bottom of the cakes are sticking to the paper case and then when I do pull that bit off the cake is just crumbling but the crumbs are VERY lite & fluffy.

What am I doing wrong?? The only thing I have done differently is used different cake cases (heavly patterned/dyed) and I have added cherries.

Age of flour/eggs?

The eggs were bought today and I am pretty sure the flour is ok too

Cake cases then? I once made chocolate fairy cakes and they were awful. They tasted of chemicals and the kids handed them striaght back. I'm sure it was the cases.