I'm trying to get sound on my television
I'm using this equipment:
- T61
- Advanced Minidock 2504 with DVI-D port
- DVI-D-to-HDMI cable
- television with HDMI port

The picture works fine on the TV, but I get no sound there.
I thought DVI-D includes sound.
Or do I need a separate audio cable as well ?
(TV has RCA sound-in ports)

Well, HDMI can carry sound, but not DVI it seems.
A 3.5-mm-stereo to dual-RCA cable connecting line out / speaker on the dock to RCA inputs on your TV should give you sound. Now getting video from HDMI and audio from RCA to play simultaneously on the TV might be a problem...

Thanks, I thought as much.
Using the above 3.5-mm-stereo to dual-RCA cable did the trick perfectly.
My TV is bolted against the wall and I could only "feel" my way around the ca. 30 connectors at the back, to find an input RCA-pair that worked.
It's for a unit that I just sold, the buyers will be happy (they got to find their own audio-input on the TV).