I think I have found a cure to the chart problems. I just updated java and it seems to have helped with the bad bars at the end of the trading session.
I uninstalled java, rebooted, u[dated and installed java, rebooted. seems to have helped. Latest java version is 6.0.260.3. You can find out what java version you have by going to the start menu and doing a search for java. Just hold you mouse over the java.exe and it will show you what version you have.