Fault occuring on use of VIX (Vestris)

I have an application which runs fine on my local development machine but when I run it within a VM (specifically my VI server) I get a fault and my application blows up. This happens on a call to the VixCOM dll (via the Vestris.VMWareLib wrapper).

    VMWareVirtualHost host = new VMWareVirtualHost();

    host.ConnectToVMWareVIServer(hostName, userName, password);

I've re-installed VIX and this makes no difference; the version I'm using (1.6.2) is the same on both my local dev and virtual VI server machines.

I suspect something weird is happening in one of the threads somewhere in the VixCOM dll but I've no idea where or how as it just causes a fault and dies.

Has anyone else come across this before? Any ideas why it might work fine on my dev machine (XP SP3) but not on my vm (XP SP2)?