Comfirmed bug for that certain item? or the vibroknives all together?

I have tried out artifice and cybertech to the high 200's on my toons, and have never really had issues RE'ing items to learn the blues, and purples. Even level 35 items. I am now trying out Armstech on my Operative and have gotten Armstech to lvl 220. I have been trying to RE the green lvl 25 vibroknife ( Knife of agile demise ) to learn the blue version of it, but after 57 tries... yes 57 tries... i have yet to learn the blue. It doesnt seem right since other Crafts i have tried, i havent had to RE more than 10 times to get the upgraded schematic. The blaster rifles i havent had any problem with either... Anyone else experience this issue?