I have a dual-boot setup with Ubuntu (lucid) and Windows 7. I have the Windows file system shared on Ubuntu through Samba.
Occasionally, I am working on Windows and my machine will go into hibernate (i.e. when the battery level is critical). By default, my GRUB settings boot me into Ubuntu. So when I get back to my PC, sometimes I just hop into Ubuntu instead of going back to Windows. However, if I write any files to the Windows file system during that Ubuntu session, the next time I do go back to Windows (which resumes from hibernate), those files are missing.
Obviously, the state of the actual file system and the hibernate snapshot become out of sync, and Windows chooses the hibernate snapshot, overriding any changes I may have made thru Ubuntu. For now, I've disabled the hibernate option in the Windows power settings, but is there any utility I can use to get back some of those missing files?