@system11
Is the A2320 displaying on an LCD screen?
This kind of banding is typical with old days scandoublers used on modern LCD screens.
As LCDs are inherently digital, they must sample the analogue input signal and typically they will only perfectly recognise some standardised VESA modes.
For "uknown" (yet still displayable) modes the likely mismatch between the engaged sampling period and the actual pixel clock will create a beat-frequency effect manifested as (perfectly periodic) banding.
Toying around with the LCD's "clock" setting may sometimes yield slightly improved results.
