Sandisk cruzer. Yes, it did work prior on my old emac with Panther macosx v10.3.9 and on a new

Question

Yes, it did work prior on my old emac with Panther macosx v10.3.9 and on a new imac.Sometimes it would eject fine and other times after I ejected it andafter the icon disappeared, - It would bring up an error message thatit was ejected wrong and might have problems.That is what it said yesterday and when I tried to use it again - The only icon that shows up is the u3system.How do I get the sandisk cruzer 2.0 titanium to show up on desktop - only u3 system shows.