Problem with beams

Dear sirs! Excuse me my english. Could you please to help me! I had a problem, I don't know how to correct it. I couldn't deal with group of notes and after my some actions automatic association of the eighth a beam changed: a bar the 2/4, first and third the eighth - pauses if I connect the second and fourth the eighth by beam, notes of one height have a beam with a slope, and notes of different height unite a horizontal beam. Was on the contrary earlier! Once I tried to return the program to factory settings, still tried to delete the program and to install it repeatedly, but everything remained still incorrectly! Thank you very much! Best wishes! Vladimir!