Hello. I have an Alu iMac (20", 2GHz, 10.5.5), which should have a Gigabit Ethernet port. But whenever I connect the iMac to my MacBook via Cat5+ cable, either directly or via a Gigabit router, I only get 10 to 11 MByte/s. The switch shows that a Gigabit connection is enabled to the MacBook, but only a 100Mbit connection to the iMac. Do I have to change some settings on the iMac or what?