At the last regular meeting John Carter said that running Windows in VirtualBox does not access thumbdrives. Here he goes into more detail: "It is true in only one aspect. Plugging in a thumbdrive won't show up in My Computer as an available device. Two things have to be done to access any device plugged into a USB port.
"First step. Go into the VirtualBox Settings for the Windows OS and click on the Shared Folders tab. Click on the plus sign on the far left to add a new shared folder. In the Add Share pop-up, click on the down arrow for the Folder Path: field, then click on Other... . In the browser window that pops up, select the drive associated with the USB port you want to access. Give it any name you want in the Folder Name: field. Optionally, make the shared folder permanent (this is useful if you are using an external hard drive that is always plugged in). Click OK.
"Second step. Start Windows. Open My Computer. In the menu bar, click on Tools. Click on Map Network Drive... . Select a drive letter. Click on the Browse... button. In the pop-up window, click on the plus sign for 'VirtualBox Shared Folders.' Click on the folder that corresponds to the drive you want to access. If the OK button doesn't highlight right away, double click on the folder name to open the folder and wait for the folder to show the contents. At this point, you may have to double click on any subfolder to get the machine to respond (make a connection). Click back on the name of the drive you want to access. The OK button should now be active. Click on OK.
"You are now connected to the device plugged in to that USB port.
"You do not have to go through all this if you are using Parallels. With Parallels, when you plug in a device in a USB port you get a prompt that asks whether you want to access that device with the Mac or with Windows. Always choose to use with the Mac. Parallels will make it available to the Windows OS."