It seems that this spell isn't working. I cast it and then checked my stat sheet and no bonuses were given. I also did a tumble check and the modifier wasn't changed at all.
it works fine. Tumble requires training. Meaning you need at leastone rank cross classed to benifit from it.
I have points invested, it still didn't work. At least one other person said they had issue with it but not sure if they had invested points or not.
It has been reported before - I myself also experienced this a good while ago. Upon testing a bit later though it worked fine, so I figured the issue had been resolved. Perhaps not!
Just tested it again and it works now. Maybe its just initial use or something.