Yea you hit the pleateau effect Lobo, basically your body has gotten use to your routine. Now it's time to mix it up to continue the weight loss. I wouldn't change the diet too much, but just switch the exercises around some. Try mountain climbing, swimming, or other forms of cardio as something different from your regular routine.
And about the weight flucuating, nah don't worry about that, it's mostly just water weight leaving and returning. Even fitness guru Tony Horton says your body weight can flucuate 10 pounds high or low (depending on the person). I switch from 225, to 222, to 229 all in the same week also, so don't feel bad or nervous if it does have you feeling that way. Usually just let your clothes do the talking, and if they are getting tight on you, then it's time for a change. But a difference in cardio training should be ok for you though.
On a side note, and this relates sort to the same thing, but people get discouraged when they see their body weight change radically, that's why alot of coaches don't recommend checking the scale maybe every week or two.
