I have the same problem with Acer Aspire R3610 - Ubuntu 10.10 - x86_64.
~/bin$ lspci|grep USB 00:04.0 USB Controller: nVidia Corporation MCP79 OHCI USB 1.1 Controller (rev b1) 00:04.1 USB Controller: nVidia Corporation MCP79 EHCI USB 2.0 Controller (rev b1)
All USB disk need to be unmout/remouved twice in nautilus.
I have the same problem with Acer Aspire R3610 - Ubuntu 10.10 - x86_64.
~/bin$ lspci|grep USB
00:04.0 USB Controller: nVidia Corporation MCP79 OHCI USB 1.1 Controller (rev b1)
00:04.1 USB Controller: nVidia Corporation MCP79 EHCI USB 2.0 Controller (rev b1)
All USB disk need to be unmout/remouved twice in nautilus.