I took A4Tech NB-99 as a replacement for the mouse due to its advanced age, not a presentable appearance of the latter (coating wear) and problems with paintwork. Increasingly, I'm thinking about returning to the old mouse - figs with him, which is already terrible, but it doesn't swallow clicks and works out the movements normally. : The cause of the above problems was found and eliminated - the power connector from the battery compartment is not firmly inserted on the board, apparently, they messed up during assembly. After fixing the defect, it works well.