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There have been/still are? issues with the AF-S 24mm f1.4 (focus accuracy problems at close focus distances), light leak issues with the AF-S 24-70mm f2.8 through the focus distance scale window. 

Last Canon lens I remember having an operational issue was the EF 70-300mm f4-5.6 IS USM. The 1st production badges could suffer from a bad optics shift when used in vertical orientation, the issue was quickly resolved and early lenses were repaired/replaced. That was in 2005.