Locked NTFS files or appearing "in use"

Hello, I have problems with files getting locked or appearing "in use" on the NTFS volume.

My setup : The NTFS disk is in a TVICO dvix slim S1 media player :
http://www.tvix.co.kr/ENG/products/HDSlimS1.aspx

The mac used is a recent mac book pro with Mac OS X 10.6.5

What happens is that some files get a lock or "in use by MAc OS X" status, and I cannot read them anymore from the mac (Mac linked to the dvix by USB), some of them I can read them from the tvix, some not
Edit : no in fact I cannot read any of these files from the dvix, however these locks/in use status appear after I have been able to read some of these files properly on the dvix

Anyway to remove these locks/status ?

Thanks for any help in advance !