You might just have a corruption of the mfs filesystem.
might be of help if you want to run the MFS equivalent of chkdsk/scandisk, although it doesn't relate to the exact problem that you are having.
Windows 7 MCE, 2 x Freeview Tuners, 1 x HD Freesat Tuner, 1TB Hard Drive, 1.5TB Mirrored Raid on e-SATA.
1 x Xbox360 MCE Extender.
1 x LinkSys DMA2100 Extender.
1 x Broken TiVo.