Root trying to overclock

[JCaM]

yesterday i rooted my g1 with the guide provided by theunlockr.com. after the process was complete my phone was back on 1.6 automaticlly (i dont know if thats the problem). now im trying overclock and am running into an issue, i installed "SetCPU" when the su request screen comes up it stays blank and always force closes. im not having much luck finding a solution so far as my computer prowess is not the best.

Do i need to be on 1.5 for this?
Could i have rooted wrong?
anyone have some insight on this?

any help would be greatly appreciated, i can be reached by gmail or gtalk:
cambo151

thanks,
JCaM