VMRC 5.1 using IE 9 cannot retrieve local drives

I am using the newly released VMRC 5.1 to connect to a VM.

In order to connect the VM's cd drive to the local machine's cd drive I am following the documentation and use these calls:

var localDevices = vmrc.getPhysicalClientDevices(VMRC_DEVICE_CDROM | VMRC_DEVICE_USB);

The above call works fine on Chrome 21 and Firefox 15 and gives back a list of local cdrom and usb drives.

Running this code in IE 9 does not return anything nor there is any error message.

The machine is running Windows 7.

Any help is appreciated.