Fly mode disables tool enhancements

[JamminR]

I have a diamond pickaxe enchanted with unbreakable 3, fortune 3, and efficiency 5
When in fly mode, the pick axe acts as none of these enchantments are working.
I most notably see this for the efficiency enchantment - when in fly, blocks seem to take normal speed (before enchantment) to break, as to when fly is disabled, the blocks break quickly as expected after enchantment.
Changing fly keys and swim mode (though written for creative, tried anyway) do not assist.
Only disabling fly mode re-enable the enchantments.

[1337Zero]

Not sure this can be fixed easy, because its as i know a feature of minecraft (fly on a normal server with unmodifyed client has same effect)