Hum from DVD video cable

Yesterday I connected a dvd player to my stereo system.I
connected the audio cables to my AES AE-3 preamp and the video cable from the tv to the dvd player.When I turned everything on,there was a very loud hum coming through my speakers.I checked to make sure everything was set up
correctly.The hum continued even with the volume turned down.I removed the video cable from the dvd player,and the hum stopped.Is this a problem caused buy a poorly shielded
cable or could it be a ground problem?
Sounds like a ground problem. They are common and the more stuff you hook up the more likely it's going to happen. They can be no fun. Try lifting the ground to the dvd player by using a cheater plug on the dvd player and see if this works. Then do it also on the tv. If you have cable tv this can be the culprit. If not do a search and you'll find lots of other ways to deal with it.
A couple basic thoughts:
1. Have you checked the cable making sure it is not defective?
2.Are you hooking up the video 'out' from the dvd to video 'in' on the tv?

It sort of sounded to me like maybe you hooked the wrong cable up to your dvd player. Hope this helps

Can almost guarantee that it is a ground isolation problem from you CATV connection, which derives its ground reference from a different source than your local electrical ground. Therefore, your audio system and video system are seeing two different ground potentials: a nice annoying hum.

I just solved a similar problem with the simple insertion of a small ground isolator made by Jensen Transformers (~$50-$60) into the video coax. It is completely compatible with digital cable television and HDTV as well.

Good luck.
I agree with Murphthelab that if you have Cable TV coming into the mix, it is likely the problem.

I used a simple solution from Radioshack. I am at work on lunchbreak so do not recall the exact connectors required, but they were about 5 bucks total cost and it works perfectly. Simply a connector you put on the cable line where it comes into the house, which goes between that cable and another cable run to your TV. It somehow fixes the problem and does not require you to you use cheater plugs on any equipment.

I am sure someome here knows the exact names of the coax adapter/connectors to use.
Lkdog's solution is also valid (previous posts have provided some details, also search the Net), but NOT if you are using digital cable service. The bandwidth is not adequate. In either case, you would in effect be implementing a ground isolator.