Welcome Jason.... [smiley=thumbsup.gif]
Sounds like you might be dosing a little light on mate. Try increasing the dose a little at a time until you reach a point where after locking in the Group Handle and removing it without pulling a shot, you notice it is just being disturbed by the Shower-Screen. When you reach this point, go back to the previous dose which should be close to ideal.
Your finished product after grinding should feel similar to table salt when rubbed between the fingers and is a good starting point. I hope you are using high quality, freshly roasted beans there too Jason. Stale, old beans will certainly create similar difficulties to the ones you are describing. If you arent already, buy a pack or two of some of the great beans on offer from Andy at BeanBay, or one of our highly respected Site Sponsors listed over on the L/H side of the page....
Anyway mate, see how you go and let us know the outcome. All the best :)