By using procexplorer I found out why. I'm still researching, but due to vista being kindof new I have not found out how to fix it.
During one of these attempts the following handles were open by the process 'system'.
With a little digging, I found out this was part of vista's new "transactional ntfs' filesystem. Does anyone know how to disable this for a single partition (or flush it to the point the handles all clear)? Without forcing these transactions to flush, the only alternative is to restart the computer. I don't like doing thatH:\