Have 2 Sandisk flash drives. Worked great for awhile. One quit before I found out I should use a USB removal tool for taking them off of an XP system. So - got another, religiously use the removal tool. Also used it on a 98SE system where everyone says no tool required. Now the 2nd one has quit accepting files. I can still read and copy FROM the drive, but can't copy or move anything TO the drive. And it's only 1/2 full. Says the file can't be created. What's up with these things!? Should I get another brand, or can I fix this one? And if so, how do I avoid this? Thanks!