Dell 1510X doesn't start when connected via HDMI

Hello,

I have the problem that my dell 1510X doesn't start when connected via HDMI zu a pc (OS: WinXP SP3). The power button is flashing amber and temp+lamp are permanently amber. There are no further reactions of the device. When the beamer isn't connected to the pc or the pc ist started AFTER the projector, it works normally.

I hope anyone can help. Thx