Contradiction with Job 14:1
Job 14:1 describes life as full of trouble, contradicting the protection and safety implied in Psalms 66:9.
Job 14:1: Man [that is] born of a woman [is] of few days, and full of trouble. [few...: Heb. short of days]
Contradiction with Ecclesiastes 7:14
Ecclesiastes 7:14 mentions enjoying prosperity and considering adversity, suggesting life's instability, contrasting with Psalms 66:9's implication of stability.
Ecclesiastes 7:14: In the day of prosperity be joyful, but in the day of adversity consider: God also hath set the one over against the other, to the end that man should find nothing after him. [set: Heb. made]
Contradiction with 2 Corinthians 4:8
2 Corinthians 4:8 discusses being troubled and perplexed, which contrasts with the preservation from slipping described in Psalms 66:9.
2 Corinthians 4:8: [We are] troubled on every side, yet not distressed; [we are] perplexed, but not in despair; [in despair: or, altogether without help, or, means]