ziped down the blank project. I am using a real machine, i do have virtualizing software on this computer but im not running vs or netduino through it. I'll try going back to the 18.104.22.168 and se if i can get the debug working again.
We'll attach this issue to the v4.1.1 (pre-beta) firmware bug tracker... I don't think we seen this sort of issue anywhere else, so we'll need to get some more info (operating system etc.) and maybe even photos/video.
We'll have to figure out where to start to understand what is different in your case.
In the meantime, let me know if you can set a breakpoint on the "blank solution" when used with the 22.214.171.124 production firmware...and if you can get debug to work again back on the 126.96.36.199 production firmware generally.