No such thing happening here.
Some possible reasons:
- your mouse may be in fault, battery, IR connection, dust, ?button?,
- your CPU may be too busy, check a CPU meter (e.g. in the Task Manager),
- R U on WLAN? Try a cable connection to the modem / router.
- Using Chrome? Two Flash versions might be active due to an update. Check and search for cure on "Pepper Flash".
In order to ease CPU load, close other programs, close other browser windows. It does wonders to have nothing but one browser window open.