I have used Freebyte to back up my docs on XP onto a flash drive. Recently when I try to back up, the program just skips everything and 'updates' very quickly. I have tried different settings and I have >2GB on the flashdrive free so am puzzled. Can anyone help?

I don't know anything about that software but do you have the software set to do a full backup or is it set for differential or incremental? Neither of the latter will do a full backup. A differential will update all files created/updated since the last full backup and an incremental will update all files created/updated since the last update be it a full or incremental. To get a full backup you need to have it set for full backup. Other than checking that please reply with your system information.