How to make a full backup of developer unlocked WP7.8 with Win XP?

[Sensonic]

I've been trying to make a full backup of my developer unlocked first generation WP7.8 with my Win XP.
I've now 32Gb micro-SD card inside my phone but would like to upgrade it to 64Gb so that's why I'd need to make a full backup (with all isolated storages etc.)

I've tried the following homebrew apps to do that:

-Windows Phone 7 Zune backup tool v.1.9
-WP Easy backup

Results: the first one gives me an error message: "the input string wasn't given in correct order. Please see the log..." or something similar. The second one starts when I click "backup" but after that it does nothing.

I've tried the aforementioned apps with Zune 4.7 (don't remember the end digits right now) and Zune 4.8.2345, with Microsoft SDK 7.0 and SDK 7.1, both with two Win XP machines. No help

Any advice or hint(s) how to get the job done successfully???
Thanks a million in advance!

P.S. I won't tell the name of the phone right in this first post because there's a risk my question will be moved to a device specified forum(s) where no-one will ever see it and IMO this is a general problem with all "non-jailbroken" devices.

 

[kingenu]

probably best to visit xda website