Yes, that's what I'm thinking too. The push button is dodgy. It cycles through the settings correctly, but sometimes misses the "steady" setting, so jumps from the "steady" to the "flashing" setting. At least... that's my current guess. Sometimes it seems okay.
If you bought the light from a store, I'd say return it and get another one.
If you bought it on ebay, that's kinda the risk you take, unless they'd be willing to exchange it. :-/