Can't open .vdi's. (verr_access_denied)

[Joshh]

Failed to open the hard disk /Users/josh/VirtualBox VMs/windows/windows.vdi.

Permission problem accessing the file for the medium '/Users/josh/VirtualBox VMs/windows/windows.vdi' (VERR_ACCESS_DENIED).

Result Code: VBOX_E_FILE_ERROR (0x80BB0004)
Component: Medium
Interface: IMedium {53f9cc0c-e0fd-40a5-a404-a7a5272082cd}
Callee: IVirtualBox {c28be65f-1a8f-43b4-81f1-eb60cb516e66}

I get this error every time I try to add a VDI using VirtualBox. I enter the VM Name/OS then the memory then select "use existing hard disk" and whenever I chose the VDI that I want this error comes up. However when I run VirtualBox as sudo it opens fine but I don't want to have to do this all the time. I assume its something to do with permissions somewhere but don't how to do anything about it.

Running OS X Lion 10.7.4 on a Mac and my user is an admin. I have searched everywhere for a solution but can't find anything that really helps.
Thanks in advance for your help.

[mpack]

The error message seems to say it all - the user account you are using does not have permission to access that VDI file where it is currently located. I'm not a Mac user, but the usual solution is to move the VM to the correct user area, or to a common (all users) area. It depends on whether you want other user accounts to continue to have access.