Not sure if this thread is dead, but I experienced almost the same problem with HDSP 9652. 

After a catastrophic HD failure I had to rebuild my OS (Win XP SP3).  The card worked fine for years before.

When I installed the driver (v 324) in the prescribed manner, my system would persistently hang forever at the Windows XP boot screen (the one just before the final logon screen). 

I rebooted in safe mode and removed the driver.  Now the system rebooted and I tried installing an earlier driver (294) and rebooted successfully.  The Windows device driver windows reported the card and driver were operating properly, although none of my apps, ie Sonar 8.5 would work with the card, and the toolbar app settings (hdsp32.exe, I believe) stated "RME Hammerfall DSP Hardware Mismatch!  This driver version requires a new interface firmware for enhanced functionality".  I was directed to this website for the Flash Update tool (which I already had). 

I had tried multiple times on several XP machines to run the flash program, but nothing at all would happen except for a quick flash in the process window of windows task manager, which showed the app was loading and exiting. 

The only other symptom was a window that appeared as I attempted to install any of the drivers, just before the expected "windows unsigned driver  warning" which I don't recall seeing in the past which stated windows didn't believe the driver I was attempting to install was meant to work with the hardware and that serious problems could occur.

How can I ascertain if the card is damaged, or if the flashed image is corrupt?  The ADAT and SPIDF outputs lock in sync with my digital board, so I assume that there is some functionality.  I'm usually pretty good at troubleshooting these things, but after a week, I'm ready to give up.

I have built my system around this card and would hate to change interfaces.  If I knew it was unfixable, I'd buy another one used, but I'd really appreciate any input.

Thanks.