This is a known possible rare behavior that shows up because GuardedID® works to protect you from all keylogging viruses.  This occasionally causes a “0” to appear, which can easily be cleared with no application issues. Go to “Manage” on the GuardedID® toolbar and toggle off Enhanced Mode (the default mode). GuardedID® will still encrypt your keystrokes, but you should not see any zeroes. The GuardedID® Dock icon will show a grey circle to indicate that Enhanced Mode is turned off.