I used that solid epox. It seems to have glued well and is *very* easy to apply. Even if it didn't glue well, it doesn't allow the usb slot to move at all, so it should be ok.

As for the instant-glue part, the one thing that I thought a bit late is that I could have left the plug inside while applying it. That would stop fumes from going on the contacts (if they want anyway). The instant glue seemed to fit very well under the slot.

Here are some screenshots and an off-topic "wtf" thing.

Before:


After:



And the thing: What is this???


it seems to always face down but it can't be part of the accelerometer because it doesn't move smoothly. I'd guess that it is a device to determine where N900 faces (i.e. for snooze) , but AFAIK that is not described anywhere.