Penofin Penofin turned my deck black. Internet

Last May I powerwashed my deck and applied Penofin according to directions.  It looked wonderful until it started to turn black.  By September, the whole deck was black, the parts in the sun and shade, where it rained and where it did not.  It is now Spring in Michigan, and the deck is a hideous mess.  I need to completely strip off the product and redo the deck.  This is a lot of work and expense.  Judging from other internet comments, this is a common problem.  I have emailed the company, but also reading other comments, do not expect a reply from Penofin.  Some that have received a response indicate the company says the product was not applied properly.  Mine was applied properly, according to their instructions.  In fact, it would be hard to apply it improperly.  You put it on, wipe off the excess, and it's done.  How can you do it wrong?  I am really mad about this.