I found that the entire +one hand weapon damage amplify do NOT affect daggers.
When I equip my boots with this enchantment, damages of my daggers aren't amplified (82 damages before wearing boots, 82 damages after wearing boots). But I have one sword which displays 84 damages before wearing boots, and 110 damages after wearing boots.
=> So the bug is only for daggers. Daggers are one-handed weapons, why the enchantment doesn't amplify their damages ?

I saw on another forum people complaining about this problem too.
Thanks.