each time, I try to move my members, from one forum to another, the forum where I import them, crashes.

This is what I do: I go to adminpanel in vbulletin, I select the table user or users, I don't know what it is exact, but then, I go to the NEW forum,
and when I import the query, manually, I keep on getting errors and my db gets screwed up and I can start all over again. I don't know how this can happen.

Use Impex, you need to import all the necessary tables otherwise it will get messed up.

all my tables? that's gonna take a while then.. I only want my useraccounts to be recovered. And I never used it before think I'll give it a try.

all the one's that are associated with the user table.

:classic: so, if I'ld simply import them, could that work too, or is impex really needed?

It's a good idea ;)