USB Harddrive g_vfs_done() Errors

[robert_cargil at gmx.com]

I am running 9.1RC1:

 FreeBSD system 9.1-RC1 FreeBSD 9.1-RC1 #0 r240745: Thu Sep 20 08:33:01 PDT 2012 root at system:/usr/obj/usr/src/sys/GENERIC amd64

 on a system with this motherboard:

 GIGABYTE GA-Z68X-UD3H-B3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
 http://www.newegg.com/Product/Product.aspx?Item=N82E16813128498

 I am randomly gettting g_vfs_done() errors when writing to my 2 gig Western Digital USB drives. Reading and writing work up until some point that a copy to the drive fails and I start getting an endless stream the g_vfs_done() errors. All subsequent writes to the drive immediately fail. However, reading from the drive works fine for hours after the write error first occured. The system will not shut down cleanly and forces me to hard power it off or reset it. Sometimes the drive needs to be repaired by booting into Windows 7. I've used the 2 gig drives for over a year in Windows 7 on the exact same hardware with not a single problem ever.