So ever since TASClient started crashing on unitsync I've been less than happy, but after reading reports that it worked fine on Windows 7 I installed it and discovered that it was indeed fine!
Therefore Win7 became my primary OS (instead of Vista Ultimate). Today, though, .50 started crashing for me on Unitsync again

I tried to think what had changed in the last day, and the only thing I could think of was that I had installed two programs: one of them VirtualBox, and the other Office 2007 Ultimate.
Upon uninstalling Office 2007, TASClient .50 worked again! I used system restore roll back to before it was installed (it had automatically created a restore point) because Win7 kept complaining that 'this program may have not uninstalled correctly'.
I intend to reboot back into Windows Vista and uninstall Office 2007 Ultimate from there to see if it starts working again. Things to note about my installs:
-Both Win7 and Vista Ultimate are 64 bit
-Service Pack 2 and all available updates for Office '07 were installed
I hope this helps nail down the issue...Satirik?.