There is a known issue for rate calculation issues on S566 and S508 in S32Assist.
For corporations claiming the OITC for the tax years beginning after December 31, 2013, "Portion related to current expenditures ? T661, line 513" (i.e. Amount G for S566 OITC row) should be overridden to agree with the Amount C of the same row.
Click here for the S566 workaround.