What can I do about peeling wok seasoning? I bought a carbon-steel wok, seasoned it, and it worked great for a couple weeks. Now however a small portion of the seasoning right in the very middle seems to have peeled off. While the sides are perfectly non-stick, the middle is, if anything, slightly sticky to the touch. I really hope I don't have to strip the seasoning and redo it from scratch. Any recommendations? Thanks!

Edit: I should also add that the metal underneath the peeled-off portion looks like the unseasoned wok, a light blueish grey.
The most likely problem is that you let oil pool in the bottom of the wok during seasoning, so it didn't polymerize properly.  Personally, I would scrub that portion off, and reseason only the bottom, using this method:

Heat the wok to smoking hot.
Turn off the heat, and immediately polish with a lightly oiled cloth or paper towel.
Turn it upside down to cool (this prevents oil pooling at the bottom).

A second possibility is that you cooked something very wet, and maybe acidic as well, in the bottom of the wok while the seasoning was still fairly new.  Again, the answer is to scrub off the damaged portion and reseason it.
Some relevant links for general care of carbon steel woks:

Patina burning off
When to redo seasoning
Serious Eats wok seasoning

Overall, don't worry about it too much; I find that I mess up the seasoning in my wok (usually due to too much steaming) at least once a year and re-do it.  As long as you don't scratch up the metal (use a bamboo or plastic scrubby), you can rescue your wok from any kind of seasoning problem.