Permission problems while creating VM

I had noticed this before in VMware Server but it happened very frequently today.
This is when you go to the final step in the creation process which is to power on the new VM in order to install it, you get an error saying Permission is Denied.
Now this is even when I am the owner of the folder where the new .vmdk file is to be created.
Also, it seems to just crop up out of the blue without any changes having been made.
So, right now I really don't have full explanation for this annoyance, but here are two features which may be useful in future in getting over this difficulty:

1) Of course, you must go to the folder where the .vmdk and .vmx file sare to be place and make sure that the permissions are appropriate.
2) I noticed that VMware always tries to make these files in /var/lib/vmware/Virtual_Machines/ and this last folder may very well be owned by root. So this has to be changed.
However, nearly always, I put my VMs in ~/virtual_machines/ which is always owned by me. Nevertheless, it seems you must make the first folder (/var/lib/vmware/Virtual_Machines/) owned by user before as there seems to be some adverse influence on the VM creation process if not.
I know that's a pretty pathetic explanation but it's more something to keep in mind until a more scientifically rigorous explanation can be found.