I changed the product code of my NAM XM from 0577454 to 0591814 with NSS and used NSU to attempt to update to v40 firmware. The update failed halfway, NSU said my phone disconnected (though I didn't disconnect it) and I tried to reconnect (pull battery, unplug USB, plug in USB, plug in battery, etc...) and NSU detected it and tried the update again, but same thing, NSU said the phone disconnected part way through. After the 2nd time, NSU never successfully connected again. My phone ended up bricked

so I sent it into Nokia. Couple questions though:
1) Since it's bricked can Nokia tell that I tried to change the product code?
2) Has anyone seen this behavior before when updating firmware or have any idea what happened in my case?
When/If I get my fixed phone back from Nokia, I want to do everything possible to NOT have this happen again when I try to update my firmware. I'm using Win7 64bit.... I had to install NSU in XP compatibility mode, did that have something to do with my problems? Also, in my power settings, I have the "USB selective suspend setting" enabled, does this have something to do with my firmware update problem? And one final thing, I did change my product code in the past to 0574994 just to get the v31 update before it was official for 0577454, and I don't think I changed it back before changing it again to 0591814, does this matter?
Any comments or help will be appreciated!