I have decided that the cursor goes away when I'm in my webmail. Windows 7. I increased the contrast and increased the size and tried the Control Key tip. When it disappears, the control key lies about where the cursor is.
happens with the touch pad and the external microsoft mouse which is wired.
To recreate, I am in webmail, typing a note and I try to use the arrow keys to back up in a line I have typed. The cursor looks like it is still at the end of the line but the arrow key has actually backed up my cursor. I can tell where it is by typing again. The insertion point has moved but the cursor (represented by a bar) is still at the end of the line.