Hey Jeff, my sister just had a company inject something into her crack. It was a vertical one and there was a moisture problem that came with it as well.
(OK, I just re-read what I typed... I now feel dirty all over and will be right back after I take a bath in some bleach)
(OK, I'm back now)
Anyways, here's some info.
http://www.thecrackdoctor.ca/repairs.htm