This posting is older than 6 months and can contain outdated information.
TV or stereo remotes (not just the Terratec) in general will usually 
be not as responsive as remotes made for computers. The former usually 
transmit the same signal again and again in given intervals. A press 
can only be considered to have ended once no identical signal has been 
received within that interval.
So, if that interval is f.ex. 0.5 seconds, the receiver will have to 
wait until around 0.6 - 0.7 seconds have passed before it can tell 
that you have stopped pressing a button on the remote.
If you need more precise control, you can also use an Apple Remote 
with the Cinergy T2, EyeTV and Remote Buddy.
I can't really say much on the range of the receiver/remote 
configuration. I didn't do any experiments with regards to that. What 
may considerably weaken the signal, though, is if you should have any 
kind of film on the receiver or remote (the protective kind of film 
you find on new electronic products).
Best regards, 
Felix