I haven't been having any similar problems, though I do not make heavy use of the toolbar. When you swapped out the system, did you do a complete nuke and pave (start with a fresh Windows install)?
I have seen crashing issues with G-Force and MC though, where I was able to solve it by:
1. Uninstall G-Force
2. Delete all G-Force user folders:
C:\Documents and Settings\All Users\G-Force
C:\Program Files\SoundSpectrum\G-Force
C:\Program Files\J River\Media Center 12\Visualizations\G-Force_JMC.dll
3. Remove references to G-Force from the regustry:
HKEY_LOCAL_MACHINE\SOFTWARE\JRiver\Media Center 11\Plugins\Display\G-Force
HKEY_LOCAL_MACHINE\SOFTWARE\JRiver\Media Center 12\Plugins\Display\G-Force
4. Reboot. (Maybe un/reinstall MC just for good measure and reboot too)
5. Reinstall G-Force.
Updating (or in some cases downgrading) your video card drivers (or network drivers maybe in your case) also can sometimes help.
But perhaps you just have a bug. If it's reproducible, you should send an email to: support@soundspectrum.com. They don't always monitor the forums extremely closely there, so it's good to send the email if you're pretty sure it isn't something on your system. Make sure to try updating any relevant drivers (and again, maybe downgrading to the second or third most recent driver too), and trying the above listed un/reinstall routine.
Make sure to use this template for the submission though:
Please "copy and paste" the below into your bug report:
Subject:
Bug Report - brief description of problem
Your System Information
Version of your OS: ________
Version of G-Force ________
Version of your media player: ________
Graphics hardware info: ______
CPU info: _______
Other info: ________
Detailed Description of Bug
________
________
________
Description of How to Replicate Bug
________
________
________