[Zope] Importing .zexp files

Hi, I’ve just downloaded the ZMultiTab_0_2.zexp from http://www.zope.org/Members/dgeorgieff/zMultiTab and put it in the import folder. I can see it from the import drop down list but can’t import it. Zope says “The object ZMultiTab does not support his operation”. At first I thought it was a file permission but that wasn’t it as I could import other .zexp files from the import folder with the same permission; I’m on a linux box. Any suggestions of what might be happening here? Thanks.