I've been setting up my GP5 after I hard reset it yesterday. While I restored some apps with Titanium backup, I noticed that if I keep USB Debugging off, whenever I launch Titanium Backup I get the following message: But if I do tick the USB debugging checkbox, the OS flashes the following warning: Press Ok, then go to Wireless and network -> USB Settings, I get this message: If I tap OK, USB debugging is automatically disabled, then I see the three USB connection options: Samsung Kies, Media player, and Mass storage, and can select either one (I select Mass storage). But if exit this screen, and re-enable USB debugging, I can still mount my GP5's drives (internal and SDHC card) to the computer by connecting the USB cable, then rolling down the status bar, tapping USB mass storage, then tapping "Connect storage to PC". However, if I do this, the two drive letters get changed on My PC (I had set letters near the end of the alphabet), meaning that the computer sees them as different drives. Disabling USB debugging and reconnecting to computer restores the original drive letters. In either case (USB debugging on and off) I can copy, create, move, and delete files normally on both drives. Bottom line: Should I follow the OS's warnings, or Titanium Backup's? For normal daily usage, considering my GP5 is already rooted and I don't plan to install any custom ROM, I don't think I gain anything by keeping USB debugging on. But then why does TB warn that leaving it off can cause problems? What problem, if any, can be caused by leaving USB debugging off?