[5ash (Philip)]

I have been stacking some sony nex 5 , arw converted to Tiff files. At first they stacked fine but now come out washed out and overexposed. The histogram is towards the right hand side whereas before was to the left.some semblence of normality with colour can be attained by inverting the curves tool (curves to the right and down)instead of up and to the left. this even happens when i retry pics that stacked fine before. Have tried reloading/downloading DSS but still the same.
any ideas philip
ps have never had problems with this software , the first pic below is one of the pics stacked ,the second is the result