Does the monitor have 2 inputs? I recently got a tft (brilliant) that has a normal input plus a DVI input, the graphics card also has to have a DVI out. If so you could try using this instead.
If it only happens on booting I would guess that it is something to do with the drivers when they are being loaded. If in normal use it is fine then I would say it's nothing to worry about, if you are not happy talk to the manufacturer, not the supplier, manufacturers are normally more helpful.