Enter the amount only once in Box 48 on the T4A screen. Choose either Business or Professional fees which ever is applicable. Then complete the corresponding schedule under "Income" > "Self-employment" to arrive at the correct taxable income.

Thanks but I have only entered the $4100 in the one box (48) on the whole return. It doubled itself so when added to my other T-4 (non-self employed) income, my total income shows as $4100 more than I actually made. I'd really like to know why. I haven't completed the T2125 yet, but I don't think that addresses the doubled income entry issue.