I'm dealing with a similar issue, and also using XP. If I connect using Firefox or MSIE, I can use the keyboard and move the mouse, but I can't click with the mouse. If I connect using Google Chrome, I can click with the mouse, but can't type.
Firefox keeps prompting me for an add-on but never installs it. Google Chrome keeps telling me to adjust my settings to allow java and activex, but nothing happens when I click on the wrench icon.
I am having the same problem which started a couple of weeks ago. I have two computers that I remote to and have had no problems up until the last 2 weeks or so. My mouse movements work fine but if I send any keystokes nothing happens on the remote computer.
I am using LMI free on WinXP with all of the lastest updates along with Mozilla Firefox. I have disabled ZoneAlarm but that didn't resolve the problem.
Any help on this matter would be greatly appriciated.