The 'pointy' longsword that is dropped by some NPC Brigands can't be smelted. I have no problem smelting other items they drop, so I don't think it's me.
I don't know if this is accurate, or has been reported before (my search threw up loads of irrelevant results) but thought it worth a mention.
Pic attached -
![Image](http://lh6.ggpht.com/_LgDs1sxZchw/TKdtCzJLgII/AAAAAAAAAhg/LUAIAbD5580/Rose%20Royce_10-2_18.29.jpg)