Miltassia Shelob shriveling bulbs

[Gold3nku5h]

I bought an orchid at a local wild oats, and some of the bulbs are shriveling. The one that blommed is nice and plump looking. Another larger bulb is shriveled and may or may not have flowered recently. Does this mean it is dying, or is just a sign of age? Some other bulbs are smaller and also shriveled, does this mean it may be underwatered? I try and keep it evenly moist all the time, and am about to start fertilizing it pretty soon. I bought some shultz orchid food because i couldn't find any dyna-gro, or dyna-bloom. At the flower shop that i work at, they have an oncidium and its flowered on a shriveled bulb. Other than that my plant looks really healthy, Being visually unappealing, it makes me think its in less than perfect health. Is there anything i should do or look out for to help it? I am about to divide the plant after the flowers drop, there are 10 total ranging from seedling, to flowering size. Also, should these be somewhat crowded in their pot, or could i pot them on a piece of driftwood/cork bark?
Thanks for helping all, i really like to read what you have to say, Aaron