The Enter key on my IceBook suddenly is acting very strangely. The bottom-left corner of the key doesn't want to make contact and feels very stiff. It's as if the key has gotten slightly popped off its contact thing-y, but I have no idea how to pop it back into place; gentle pushing, pulling, and lifting from various directions doesn't seem to be doing the trick. Has anyone else experienced this? What should I do to fix it?