senchalabs/connect — pull request #421 by shinuza (2011-11-23 20:39:26+00:00)
Title: process.memoryUsage().vsize was removed in node v0.5.10

This is why connect.profiler will print something like

memory vsize: NaNgb

[Source](http://blog.nodejs.org/2011/10/21/node-v0-5-10/)