Dear freckles,
It does sound like it's another flare. The leg weakness you describe has, for me, always signaled another flare. I'm not a doctor and can't tell you for sure what's going on, but I can give you my opinion based on my own experience with and knowledge about flares and prednisone.
I've always taken oral prednisone for at least three weeks for a flare; I start with eight 10 mg tabs a day for a week (80 mg per day), then taper down by 10 mg every three days until I've taken the last pill. It sounds like you took a much larger dose than that--240 mg a day if you took 10 mg pills--for three days and then stopped without tapering. Suddenly stopping such a high dose can really send your body out of whack and, according to my doctor, you risk adrenal shutdown without tapering off.
What's more, if you were only on prednisone for three days, that's not a long enough course of steroids for a flare anyway, regardless of the dosage, you should have been on a taper for three more weeks at the very least to keep the drug in your system. A steroid treats nerve inflammation, and this brief course you took might not have been enough to quiet it. Since it has been a month since your last flare, this could count as another flare.
Tell your neuro about the leg weakness. You might have to take steroids again. If so, ask about taking a longer burst and taper this time. I know how difficult the side effects can be while on steroids, it can be really rough. But remember that all of that is temporary. It's worth the discomfort if it will keep the flares at bay.
I hope you'll let us know what your doc has you do next.
Kim