Cannot single step in debugger?

Hello,

I am using IntelliJ Ultimate (both 13 and 13 EAP), and I have an interesting situation when debugging a node.js applicaiton. I am able to set breakpoints, and the debugger properly stops at the breakpoint, however I cannot single step *at all*. If I try to step over or step into a statement, then it seems to have the same effect as if I had simply run the application.

IntelliJ v13.135.815
node.js v0.10.14-pre
NodeJS plugin 135.790

Any and all help appreciated!

Regards,
Paul