Hi there.
In the Alpha page 52, Designer Notes Presige Skills section, it states "Whenever a prestige class calls for a number of skill ranks,
you can qualify for the prestige class if you meet that number
of ranks –3 if you also have the skill as a class skill. If you do
not have the skill as a class skill, you must possess double
that number of ranks."
I would suggest changing that to "Whenever a prestige class calls for a number of skill ranks, you can qualify for the prestige class if your ranks plus class skill bonus at least equal that number of ranks."
That requires the same number of skill ranks for class skills, but seems to make more sense for cross class skills. It's also more consistent with the general +3 equivalence theme.
Just my two cents worth. ^_^
BrokenShade