[Psycogeek]

Your actually awaiting a responce from somone who knows what they are doing :-) i can only guess.

in the mean time, what you relayed in your post looks like the usual memory corrupt or not as described.
to use this thing AVOID the areas of memory that dont work, AKA work with the 1.8g that you actually have :-(
Sorry looks like you (like thousands of others) got screwed.
Get your money back if you can/want. if you dont then use what really works of it and go on, knowing that it will "get you by", if you avoid going beyond a specific storage size.
one way to do this is to assemble your ACTUAL memory ammount on your main computer (in a folder), count it out and know that it is the right size (or smaller), then copy it over to the cleared space on the unit.

it is likly that the reason you place VIDEOS on it breaks then is because videos are BEEG, so you notice it most when you try and put those on it.

some devices you can HACK them to ID the actual memory then you get memory FULL instead of other errors, but the results are the same, only parts of the displayed memory are even available to you, corrupt or non-existant after that.
Dont Push it, if only so much memory works/exists on it, then only USE that memory, trying to put 50 eggs in a 12 egg basket is just going to break the eggs :-)