JDeveloper and displaydatg 1.0

[dotneto]

Hi,
I'm trying to built my application in JDeveloper. I use diaplaytag1.0 to show information, and it used to work in another computer. Know i have it, and i had to add all libraries again, and tag libraries. Everithing else worked but the display tag. I get the http: sourceforge.net.... is not a tld registered namespace and all that. I know that it is a library issue, but i'm adding the display tag i downloaded from source forge but still not working, it doesn't even built.
I'm not expert in managing libraries in JDeveloper, by the way(you should know that already)
Any idea, help, advice...?\

Thanks