I was trying to edit the fields in Tools > Options > This File according to the instructions for setting up Dropbox file sync.
However, I discovered that I unable to change any options in the Options dialog except for checkmark options.
For example, in Tools > Options > This File > Background Recalc, I am able to check or uncheck the checkbox.
But for "Auto backup every x minutes", i am unable to change this value from the existing value of 10. I've tried single-clicking the field, double-clicking the field, pressing F2, typing in a number, trying to click the up/down button that momentarily appears in the field - nothing works to activate this option to change the value.
The same thing happens when I try to select a folder for the "Sync Folder" option.
UPDATE: I just discovered that I can activate and