I think I found 2 errors.
1. p7 the u and d formulae are missing an h
2. p12 I don't believe that d(lnX(t)) = dX(t)/X(t). I'm still not sure why this is incorrect but looking at the solution to the sample question 12
d(lnX) = (alpha  .5*sigma^2)dt + sigma dZ
Also, disregard perpetual options and add S^a claims
