Ive tried it both ways several times , and get the same results (1)ED-E will fast travel with me, but will not move from the spawn point. (2) ED-E will no longer attack even when he is attacked.(3) quest goes inactive with no notification of completion or failure. If anyone knows a way around this bug please let me know.

I've had a few problems with ED-E so far.
The first, when I exit a building, random friendly mobs will be there from out of nowhere, and attack ED-E.
Secondly, ED-E goes aggressive out of nowhere, and just goes ape on whatever is nearby, friendly or hostile.
And the most aggravating so far, his inventory keeps fluctuating from 360u to 120u, and anywhere in between, deleting the excess weight gear.

Did your problems start before or after you had him upgraded?

I noticed the attacking mobs today with two different groups. At least they dispersed while he was unconscious, and I fast traveled when he woke the second encounter. I had assumed that the Followers had done something but I still can't get my companions to be 'passive'. So maybe its a glitch instead of the followers :shrug:

The problem i've had with him after the upgrade is that he keeps getting stuck in the top of doorways. It makes it hard as hell for me to get past/under him to exit rooms with one door and sometimes if i leave a building, he stays stuck in the doorway graphic inside the house. The only way around this is to fast travel and then return to where i was, then he reappears outside again. I never had any problems with him until after he was upgraded.

I'm having the exact same problem. Once I pick ED-D back up at Primm he'll be just fine. I'll finish the quest, and move on. But then the very second I get into a fight, ED-E will lock up. He won't move, he won't attack, nothing. If I fast travel he'll come with me, but he won't leave the spawn point.

From what im seeing this bug is mainly present in the pc version?

http://www.gamesas.com/index.php?/topic/1133524-ed-e-strip-casino-glitch/

there's a bug where the casinos don't re-enable ed-es weapons and don't give companions back their weapons, only yours

I had ED-E go completely postal after the Brotherhood mission. Had to put it down.

Apparently it's also in the 360 version, much to my distress.

No It's not just the pc version, I have the 360 version and I'm having most of those problems also. For instance, I let the fellowship study him and upgrade his weapons, and when I got him back all of the items had disappeared, and some of them were named weapons and armor. He's constantly getting stuck on stuff, and now it's a rarety if he even gets involved in a battle. Mostly he just sits there while Boone and I fight off everything. And lord don't get me started on all the other glitches in this game!!!!

This is probably the answer, as im almost positive that I fast traveled to hidden valley directly after exiting the tops. thanks for the reply,ED-E is banned from the casinos on the next play through.