Did you do the full shout? Otherwise I don't know what to tell you. You've tried everything else, it seems.
Well I'm doing what others have said to do and nothings happening except a slight rumble sometimes but apart from that nothing. I'm probably missing something but as soon as I learned the shout I got back to Tamriel and used a soul to learn it, found a big empty space and used the shout first at my feet and then further away on the ground but nothing. Damn dragon just hates me I guess.
Im not sure man but he summons on the ground like a conjure spell. But you seem like you know this........ummmm i used a kinect to summon him. Dont know if that makes a diff but i enjoy using shouts yelling the actual dragon lang at my tv baha.