Pool questions(water is cloudy even though chemistry is perfect)?

Had our pool plastered(marcite) in may 07.pool started getting very cloudy in june.We have our water inspected and tested every week by professional company. The ph, alkanility, calcium, TDS and bromine was perfect. the water still would not clear up. When we vacuum the pool with automatic robot we find that there is lot of white dust(plaster dust?)in the vacuum filter. Changd water and power washed and removed all the plaster(?) debris in oct07.Within a month water was cloudy.Chemistry is perfect but water is still cloudy. in the vacuum filter i can still see lot of white sandy/chauky paste. Do you think the water is cloudy because of plaster mixing with water? bad plaster job? I am not sure if that is plaster dust though?What should be do? Change water again? Is the plaster causing the problem? I wonder why the filter wont remove the plaster dust. Sand in the filter is new. pump is working fine. Change the water again? Paint the pool with epoxy or something or replaster ?