Mike,
I've had the same problem for about 6-9 months now. I do not use Excel on a regular basis as I'm not in an accounting or data tracking posistion. However, I do use a simple excel spreadsheet and other files that are set up like a printable form for our crews
to use (very very simple file using cell outlines and plain text). I tried your "F8" command, but this does not correct the problem, however it does allow for expanding the cell selections by however many were not intentionally highlighted, but not reducing
the undesired cell selections.
Typically I will be working in a file using my cursor to select individual cells to input data into, then out of the blue, multiple cells will be selected. The number of cells seems to vary as well between 2 and 6 cells in a column selected (never in a row).
It doesn't matter if I select in the center of a cell or the outline of the cells. The only generic way that I have found to negate this is to zoom way in on the page and that seems to stop the undesired multiple cell selection, at least for a time that is.
It also does not seem to be on a given number of clicks of the mouse, cells, rows, columns or in specific files for that matter. What is also strange is that the affects do not carry over to another persons computer should I email the files to co-workers
to try and get the files to start the same thing. Sometimes the multiple cell selection will not happen for a couple of times/days of working with excel files, and others it seems like I can't do anything to get it to stop.
(Really annoying when you want to copy and paste just one or two specific cells that are in the middle of others that you do not want)
I would appreciate any help that you could offer. Thank you and have a great day.