Thanks for that !!
I never tought of using Cygwin to check for permissions as I'm logged in as administrator anyway.
For C:\dsa-win I get back : drwx------+ 19 Administrators None 4096 Oct 28 ....
I'm using only a 1GB card an I tried installing in the internal storage of my Tomtom as well ,
and even with the latest DSA the result is still the same :
No problem generating the new installation but no chance to the Tomtom after that.
Tried DSA from the desktop as well ,but no luck either.
And just to confirm : I tried the V9 SE Navcore and the Tomtom boots up - I used the same 9.004.go750_blue_me_v1.CAB-navcore-GO_Blue_Me.cab and just copied the SE ttsystem over.
So I think the original cab is ok ,but something get's messed up with DSA-WIN and Vista64 ot the installation on the Tomtom.