Testem / Socket.io installation error

I updated node.js to v0.10.1. So I decided to update my global installed modules, too. Everything worked well except for Testem.

I got the error that vcbuild.exe could not be found. I found out that this error comes from the ws module which is required by Socket.io and Testem. The error message says that I should install Visual Studio 2008, but I have already installed Visual Studio 2012. So I do not understand why I get this error.

I also found out that the compilation of ws is not nessessary and only improve the speed of websockets. If I install ws by hand, I get the message that it could not be compiled but that it works without.

But if I try to install Testem the installation cancels at the point where the error occurred.

I had Testem installed before the update and never had this problem before.

Is there a solution to solve the compilation problem or to continue the installation after the error?

Thanks!