ASA 5520 connected to C3560 48G, only 100Mbps on ports

[perpaal]

Hi I have a ASA 5520 connected to a Catalyst 3560 G48. The ASA 5520 has 4 gigabit interfaces, but I can not get them to connect to the C3560 with gigabit speed. In auto mode on both devices, it works fine, but only with 100Mbps. If I lock both devices with FDX 1000Mbps, no link... Any ideas?

[devils_advocate]

I realise this may sound basic but have you tried to replace the cable?

[perpaal]

Yes, actually I have to interfaces with the same problem (Inside/Outside), both act the same way. Only about 3ft/1meter cables.