<<When converting arrows, if a stack was converted earlier in that game load, the convert arrows option is greyed out until the new stack of arrows is either sold and repurchased, or, rarely, if the skill is unlearned and relearned. This happened using Convert Arrows: Explosive, Lv. 3.>>
I'm having the exact same problem on my Convert Arrows: Fire. I have more normal arrows I've picked up I want to convert, but can't - the skill is greyed out, though the arrows are with the proper character and I have the skill (converted before). I just keep checking on my normal arrows until I find I can convert them, then do it. I haven't found a real rhyme or reason why I can or can't convert them at times, but it would help if this were fixed soon. BTW, I'm on 1.44, so it wasn't fixed on the latest patch.