I use LR3 and have just upgraded to OS X Lion. When importing images from CF card, server mounted volumes are not displayed as an import destination. Drives are mounted and are visible when in the Library module, but not visible when importing. This was not the case under Snow Leopard.
I can import the images to a locally attached drive then drag to the network volume in Library, but this requires adequate space on local drive and takes time to carry out the process.