I just installed iatkos v7 on a seperate hard drive from my vista 64 bit one. When trying to boot in OS X after a couple minutes I get a circle with a slash through it on top of the Apple logo. Any ideas what I should do?

Here are my specs:
Intel Core 2 Quad Q6600
Gigabyte GA-EP45-UD3R
Geforce 9800 GTX 512 mb
4 GB Ram
Seagate 1.5 TB HDD with vista 64 bit plus 2 data partitions on it (Iatkos is on a Western Digital 80 GB IDE HDD alone)

Thanks so much