@idarius thanks for the reply! I will try that configuration! eventhough, it sounds strange to me that you have tried the CEA mode:
# this is for HDMI_CEA_480i60
hdmi_group=1
hdmi_mode=6
If you are using a VGA monitor, should not be better to use a DMT mode?
# this is for HDMI_DMT_VGA_60 (640x480)
hdmi_group=2
hdmi_mode=4