I have a VT6421A and use Xecuter connectivity kit to get Mode B on Hitachis (SLAX doesn't work, didn't try v2).
For the most part, it works fine, have to use the external port for Hitachi drives, mine has a standard SATA plug on the back.
BUT, I have had a couple of 47DJ's that do exactly as mentioned above, locks windows loading, none of the tricks work, when it does load into windows I get an error (CODE 10 I think).
I had three 47DJ's to do recently, first two worked fine, last one decided it didn't like me..
The only difference in the drives was the one that didn't work was substantially more used than the other two and alot noisier.
Perhaps there is some hardware issue with some 47DJ's and this card.
In the end I just pulled the chip off and used a trusty Willem programmer
What would a dump of the VT6421A firmware assist in?