The display suggests that you have marked the Maximize box for a 401(k), perhaps in addition to marking the Maximize box for a SEP IRA. Either revisit the self-employed retirement contribution section, indicate that you made contributions to a 401(k) and remove any entries there or simply delete the Keogh, SEP and SIMPLE Contributions Worksheet and start over with entering your SEP contribution. In the online version of TurboTax you can delete the worksheet by going to Tax Tools -> Tools -> Delete a form and clicking the corresponding Delete link.
Note that the maximum SEP contribution for a self-employed individual is 20%, not 25% of net earnings. Net earnings are net profit minus the deductible portion of self-employment taxes (because the SEP contribution is an employer contribution that reduces net earnings to which the 25% base rate would apply). A SEP contribution of $26,650 would require $143,382 or more of net profit (assuming that you have no other job where you pay Social Security and Medicare taxes). If you have less net profit than that, you have made an excess SEP contribution that needs to be corrected.
