Recently, I upgraded the VirtualBox to version 4.1 on my Ubuntu 10.04 machine. After that, my Win7 VM instance failed to start and showed the ProgressProxy and IProgress Error. When I started it from command line, got segmentation error. So I am puzzled, tried many other option and went thru all the VB config files. But no clue.
So finally created a new VirtualBox VM instance using the old hard disk image and it took few mins only. The new VirtualBox VM instance started successfully. But still I am unable to find the exact reason for this issue.