Here's the reply from Elgato. Havn't had a chance to go through this but will post what happens.
Thank you for contacting Elgato Systems. I'm sorry you're having USB 1.1 problems.
What video signal source are you using? This issue has been happening with some older (18-24 months) international (PAL/SECAM/DVB-T) Elgato brand EyeTV Hybrids. In some cases, it's a temporary problem, but it can be a symptom of a hardware fault. At our forums, some users report heating up the device in the oven/with a hair dryer may work. However, it's a fairly good indicator that the device is faulty.
When any USB device is connected to your mac, several test signals are sent back and forth between the device and the USB controller within your Mac. After determining that the device is full speed device (USB 1.1), the connected device sends a particular signal to the controller, which the controller must respond to with a particular sequence. When that sequence is received by the EyeTV device, it then starts communicating at high speed (USB 2.0).
This problem can happen either because the USB controller does not respond to the high speed signal, or due to a problem with the USB chip in the device itself.
Try EyeTV with other FireWire or USB devices detached. There might be a fault with the connection, or some sort of conflict with another device.
Quit EyeTV into your EyeTV Archive folder and erase the Live Buffer file. Launch EyeTV again and try to open a live TV window. Are you able to test the device with another Mac? If not, try creating a new admin user account and install EyeTV for it.
If you have your EyeTV activation key handy, I would like you to reinstall EyeTV. Download this application:
http://dl.elgato.com/eyetv/reporter/eyetv_reporter_14_146.zip
In EyeTV Reporter, press the Easy button, then select Uninstall. When that process is done, EyeTV will be in a new state. However, your recordings and schedules will still be present. Then reinstall EyeTV:
http://downloads2.elgato.com/eyetvdownloads/support/eyetv_333_6040.dmg
Copy EyeTV from this disk image, and place it on your hard drive. Then, you can erase the disk image (dmg) file. Does this reinstallation resolve your problem? A device more than two years old would be out of warranty.