I've just tested Oneiric as requested and the same problem occurs there.
This may be helpful extra information. When the Cinergy Terratec T2 is plugged in and working, it has a blue power LED which is on. When attempting to suspend, this light stays on, and so does the power light on my computer. I don't know much about hos suspending working, but this may indicate that this device is not being powered down and is preventing the computer from successfully suspending to sleep.
I've just tested Oneiric as requested and the same problem occurs there.
This may be helpful extra information. When the Cinergy Terratec T2 is plugged in and working, it has a blue power LED which is on. When attempting to suspend, this light stays on, and so does the power light on my computer. I don't know much about hos suspending working, but this may indicate that this device is not being powered down and is preventing the computer from successfully suspending to sleep.