I keep my 4th & 5th rows of my inventory full of foods and needed items. I picked up 5 more rows of Cowls and started dropping them & when I cleared out all 3 of the top rows, I was still walking slow as the bottom 2 rows failed to move up as they usually do. I relogged and it had not changed till I dropped 2 more cowls. Then they all moved up as they would normally.
I play cc on a Windows 7 Home Premium 64bit PC.