WHY SOME STORED BULBS SURVIVE WINTER WHEN OTHERS DON'T? HELP

I store elephant ear bulbs in the basement over winter every year and have recently expanded to storing canna bulbs too. We merely dig them up after the first hard frost, let the dirt dry up just enough to knock off and then store them in the basement on paper in the dark. Some lay out in the open air while others are in paper grocery bags. I'm now loosing about 5% of elephant ears which is OK but I lost 75% of the cannas this winter. WHAT GIVES? There is no sign of mold or mildew, no sign of being eaten on by bugs. Although this year we did notice a higher amount of these roach look a likes hiding under the bags of bulbs. They aren't cock roaches, I've always called them water beetles as I used to only find them around basement floor drains. They have always been kept down by pouring a little bleach in the drains every month or so.
My wife has JUST informed me that there was a bunch of these bugs in and around the bulbs this year, possibly over 100 of them. EEWWW this grosses me out. I do not know if the bugs have anything to do with the bulbs or not as I see no signs of these bulbs being eaten on.

SO WHAT IS THE BEST WAY OF STORING CANNA BULBS OVER WINTER?

I'm also confused as to why elephant ear bulbs store better than canna's and why some canna's look so good when others directly beside them are dead. Man I'm so upset by this as I aquired so many cool canna's last year and tons of them. I literally had close to 10 paper grocery bags full. there were so many that we left some in the ground to die as we were too worn out to dig anymore up.I say we...I'm a paraplegic so I don't dig anymore, I just clean and package.. I'm so depressed and flustered by this and there is no way I can afford to buy more of these.
DOES ANYONE HAVE ANY CANNA'S OR OTHERS TO TRADE OR SELL? I have many Passiflora's, Datura's and Brugmansia's I could root cuttings of to trade or seeds and seedlings.
If nothing else, please help me figure out why I lost as many as i did and how I can avoid this in the future.
Thanks everyone!
Jeff

JLD,

Sound like they're probably drying out. Try storing them in pots with soil covering them. If your basement is cold they will not sprout. Cannas like moist soil and warm soil to grow, so as long as they're not excessively cold, they'll stay dormant but survive. They're hardy to about zone 7 (some say 6 with mulch), and they grow like weeds down here. I have noticed if I pull them (I have done this to give them away), and they dry out from sitting too long, they don't come back.

AHHH You know that makes total sense thinking back but I just figured they'd store fine like many others. It does appear like they simply dried out..I took my wifes word and we just stuck them on a shelf..DOH! Man whyis the obvious so hard to see until its hindsight!?LOL
Jeff