Okay I just checked Plextor’s site and I saw they have a new firmware 1.06.
Now 2 questions :
Are there any dangers if I flash this drive in an external enclosure ?
Is this version of the firmware still good at backing up copyprotected games ?
Thanks for all your answers.
About the 1st question:
No problems, I flashed my two Premium-Us.
About the 2nd… uh, I really don’t know. But it is a wise question, I pointed it out the same problem looong time ago… 
Regards, 
ET
No problem here backing up Sid Meiers Pirates! which is protected with SecuROM v5.03.06.0042. BW 4.xx did the job. 