Another techie post, sorry..
Not sure there would be anything in the import table if it's COM+? Wouldn't it load it via its CLSID? I didn't notice any imports for other NPS files either.
The downloads come from fus.samsungmobile.com, so it's a logical assumption that it's the correct DLL, but not guaranteed to be right of course.
If it's definitely using FUSCrypt.dll and the Import routines don't work, it would suggest that the crypto keys are hard-coded rather than communicated to the client. Windbg might be useful whilst performing a genuine NPSMitsBinaryUpgrade.exe download if so. Might give away the secret keys...
Since my last post, I wrote a brute force checker as I described. Nothing showing up for September yet, but it did find the following August releases (all of which we already know about). The download links are useless of course as we can't decrypt the files....
Operator: O2 UK, CSC: I7500O2UIH2, Firmware: I7500XXIH6
http://fus.samsungmobile.com/Phone_Binary/6/GT-i7500I7500O2UIH2I7500XXIH6I7500XXIH6_500.zip.enc
Operator: O2 DE, CSC: I7500VIAIH4, Firmware: I7500XXIH8
http://fus.samsungmobile.com/Phone_Binary/6/GT-i7500I7500VIAIH4I7500XXIH8I7500XXIH8_500.zip.enc
Operator: Vodafone IT, CSC: I7500ITVIH2, Firmware: I7500XXIH7
http://fus.samsungmobile.com/Phone_Binary/6/GT-i7500I7500ITVIH2I7500XXIH7I7500XXIH7_500.zip.enc
All of academic interest really than practical usefulness
Chris