Weird USB mouse behaviour.

My mini has been acting up lately. First was losing the FW port until the mini sat unplugged for over 24 hours, now it's back up, but I lose the mouse when I log out. I noticed it last night, so I let the mini timeout and go to sleep on it's own. Today it came up with the mouse intact. This evening I woke it up and had no mouse. I logged in vie the keyboard and navigated to the console and terminal with keyboard shortcuts. Nothing useful shows up there. I did discover that it responds to button presses (the menus pop up and disappear) and that if I plug in my daughters novelty horseshoe mini USB mouse it has the same reactions, so it's something in the mini and not the mice. I've tried sleeping the mini via the power button and waking it and it hasn't brought back mouse motion. I've got my iBook for basic uses until I solve this, though I am making this post from the mini, all keyboard.