Canon rebel xt flash problem

[YokotaS13]

So i picked up this vivtar auto focus zoom 728afc flash from the airmans attic today. And its for Canon, but i cant get it to work with my digital rebel. However the lens i just took out of the case from my VIntage 1984 Canon 35mm works perfect with my Digi rebel


any ideas?
these are the two flashes, i think you can tell whats from 84



Any idea?
the lens is getting signal from teh camera the auto check lights up when the camera is working in liek autofocus and stuff, but i just cant get it to work.

I just realized how good a flash is...i took a ahot at daytime speed with the dinosaur flash and it turned out as well as an exposure 5x longer

[Nemesis]

can you attach the images? I cant view them at work.