Happens to me, too. Around 5pm everyone in the neighborhood get on their computers after work and the bandwidth drops to a trickle. I ha-ha-hate cable modems.
Its not the cable modem itself, it is your ISP not implementing an effective infrastructure (overloading). My cable modem receives at 20Mb/s 24/7 and low latency.
Open trouble tickets, raise a stink, see what their service says (if they advertise "50x faster than DSL" or whatever and you can show that it is not....)
To address the OP, power-cycle your router to see if the problem clears.
I seem to keep losing connection in the game and the Wizard101 site. Server issues?
Was right in the middle of Katzenstein's Lab too. :-(
it has happened to me too (so annoying!) you should look at your server or whatever it is called. i found out i was on the wrong one :-( and if that doesn't work just don't move when it happens ,trust me. (i am a kid computer as my friends call me -) that is all i know. if it stops entirely(like for me) run screaming into the night for a mechanic. -(W101 rocks that much!)
Do you come right back? If so that's most likely an internet issue. I get that quite a bit and haven't found a good way to eliminate it but I can tell you I've gotten it in multiple online games...I don't think it's something in Wizard 101 causing it.