I ran into the 403/404 bug on my 2nd gen ipod touch ('floorpod' in the high scores list) running 4.2.1. I recently upgraded to a 4th gen ('suckerpod' in the high scores) running the latest IOS, 6.1.3.
This new bug I've encountered is similar to the 404/403 bug, except it stops me way back at level 240. When I complete that level, a window pops up that says 'Level 240 Passed. You beat this difficulty!', as well as a big OKAY button that we press every time we complete one level to go on to the next.
Except when I hit that Okay button, the pop up window simply disappears, and I'm left looking at my completed level 240. It doesn't advance to the next level. I go into the menu options where it says that I've passed 239 levels in the Challenge section. I press the Play button there, and it only gives me the option of selecting no higher than level 240, the level I just completed.
Total drag. And the developers have shown no signs of addressing the 404/403 bug (maybe that's not a bug, but they just ran out of levels/mazes, so that in effect is just a kill screen?) or interacting with anybody here in the forum, so I expect this to go unresolved as well. Oh well. I'll try to find some contact info and send them an email directly, but I tend to be somewhat cynical when it comes to matters like these.