Tal vez sea un problema de configuracion:
INSTRUCTION SET
Bit M2 Altura de caracteres
Bit FY Tamano vertical de caracteres en pixels
Bit L/F Altura del marco en lineas
pero especialmente WF que de acuerdo al DataSheet del SED1330:
8.2.1.8. WF
Selects the AC frame drive waveform period. WF is usually set to 1.
WF = 0: 16-line AC drive
WF = 1: two-frame AC drive
In two-frame AC drive, the WF period is twice the frame period.
In 16-line AC drive, WF inverts every 16 lines.
Although 16-line AC drive gives a more readable display, horizontal lines may appear when using high LCD drive voltages or at high viewing angles.
Espero lo arregles pronto.
hrosales