Please provide better details. Where is the problem? What are you trying to do? What happens / does not happen?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options) key, and then starting Firefox. Is the problem still there?

Safe mode did not help.

When using <select> with 'multiple' option, after clicking a row the mouse pointer is still active and will highlight rows when moving the cursor up or down. Unable to select multiple non-adjacent rows with ctrl-click.

In single select mode, the dropdown appears but unable to select a row. Need to click outside the control to close the dropdown.

example code:

<select title="" id="main.packageTarget:input" name="main.packageTarget" class="bodySmall" style="width: 500px">

<option value="Av Finance||i1D0B08E28D564BFD9C3EF9AB51CD53BA">Av Finance</option>
<option value="Av Sales||i8B11D110AFCE482DB28AD17BA376B162">Av Sales</option>

</select>