I've got the same bug but with Heavy Lance, here's what hapend:
I've got a heavy lance..
I buy Deadly Heavy Lance of the market for 350k..
I heirloom Dealy heavy lance to Balanced.
I notice that I can't pick it ingame so I look at webpage and it is,
Tempered Heavy Lance, with wrong stats and wrong name.
weight 1.8
difficulty 14
spd rtng 78
weapon length 190
swing damage 21, blunt
thrust damage 30, pierce
A guess could be that the site made it to Tempered instead of Balanced and since there is no Tempered heavy lance I can't choose it ingame?
I see that I also have the old normal heavy lance at webpage (can't see that ingame either) so I sell it at webpage.. Still can't pick Tempered Heavy Lance ingame, it is still there at webpage though. I bought the normal heavy lance on the webpage but I didn't loose gold and it doesn't appear on either webpage or ingame.
I now notice that I got Thick Saranid Mail boots ingame that I did not have before, in fact, I have never posessed Saranid mail boots so I can't have misslclicked heirlooming or anything like that.