Can't use two VMs at once

Hi,

I am running VMWare Workstation 10.0.2.

Ever since I have mapped one of my internal hard drives to one of my VMs, I have not been able to use two VMs at once.

The VM with the mapped hard drive runs normally, but when I start a second one (running either Windows or Linux), I have no input on it (mouse or keyboard).

If I stop my VM with the mapped hard drive, the second VM works fine without needing a reboot.

I can use my two VMs at the same time if I remove the mapped hard drive from my first VM.

Any idea what could be causing this ?

Thanks.