Fix y-coord bug due to round-off error in mouse window implementation; tweak smoothing coeff.
Fix y-coord bug due to round-off error in mouse window implementation; tweak smoothing coeff.

RTcmix/RTcmix,RTcmix/RTcmix,RTcmix/RTcmix,RTcmix/RTcmix,RTcmix/RTcmix,RTcmix/RTcmix