Check what all is running in the background. Don't have any other tabs or applications open that are not essential to playing WGT.
Make sure the Flash Player Website Privacy Panel Settings is empty.
A jumpy meter usually means your CPU is pretty busy during the down swing.
Many of us keep Task Manager minimized to our task bar so we can watch for CPU Performance to settle down before we start out down swing. Some players pause for a 3 or4 count at the top of the swing to give the CPU time to settle down before they start their down swing.