Compiz' window placement plugin I believe does default to placing all new windows on the current active monitor. However this is a problem with the proprietary NVIDIA driver, because that's one of the only drivers that treats all monitors as a single output. Because NVIDIA does not implement the Xrandr extension properly (but most other drivers do).
Please run "ccsm" and scroll down to Window Management > Place Windows. In there you will find a few options for controlling and customizing window placement.
Compiz' window placement plugin I believe does default to placing all new windows on the current active monitor. However this is a problem with the proprietary NVIDIA driver, because that's one of the only drivers that treats all monitors as a single output. Because NVIDIA does not implement the Xrandr extension properly (but most other drivers do).
Please run "ccsm" and scroll down to Window Management > Place Windows. In there you will find a few options for controlling and customizing window placement.