losing bulbs during dormancy

Hi -

I've been keeping my bulbs and re-growing them yearly, but seem to lose a few randomly here and there. I have them outside in sun with ample food during the summer, and stop watering late in summer. Then I bring them into our basement and take off the leaves as they wither. However, I noticed that one or two seem mushy, and I am at a loss as to what I might have done wrong. Any suggestions? I suppose that for some of them, I clearly have gotten it right in the past so perhaps it's random.

We did have a rainy summer and I don't know if that might have something to do with it.

Thanks!

Mushy bulbs means fungus. The rain did it.