Any success with Page Fusion?

[cb1]

Hi, just curious if anyone out there has been successful using Page Fusion. I decided to give it a shot again with 4.0, but it still seems to be broken (last tried in 3.2.10).

My setup is: FreeBSD host (64-bit)
CPU: Intel(R) Core(TM) i5 CPU 750 @ 2.67GHz (2660.00-MHz K8-class CPU)
Origin = "GenuineIntel" Id = 0x106e5 Family = 6 Model = 1e Stepping = 5
real memory = 8589934592 (8192 MB)
FreeBSD/SMP: 1 package(s) x 4 core(s)

Most of the guests are Windows 2003 Server R2 (32-bit), though I have a couple of 2008 Server 64-bit guests. When page fusion is enabled, it makes the guests that it's enabled on very unstable. Everything from spontaneous reboots to STOP errors (blue screen) to random processes on the guest crashing to hard locks. The host is fine, just the guest with page fusion enabled is affected. The behavior was the same on several 3.x versions I tried as it is on 4.0. All of the guest additions are updated to 4.0.

Is anyone successfully using this feature? I didn't see any bug reports that looked close to what I'm experiencing, which leads me to believe that I'm the only one encountering these issues. This is on different hardware than my last attempt, so I think I can rule out hardware problems.

[katapaltes]

Based on host memory consumed before and after launching guests, I haven't seen any evidence that it's working with:
VirtualBox 4.0.2 running on 64-bit Ubuntu 10.04 host with two identical Windows 2003 32-bit guests - or -
VirtualBox 4.0.2 running on (64-bit) Windows 2008 R2 host with two identical (64-bit) Windows 2008 R2 guests.
Guest Additions are installed on all guests. No guests are crashing. It almost seems the setting is not being used.

Conversely, on a 64-bit Ubuntu 10.04 host, Ubuntu 9.10 guests that have been allotted 1GB apiece only consume 400MB each, with or without Guest Additions installed, with or without Page Fusion enabled.
-katapaltes