You need the version that has 2.6 in its name. The2.4 / 2.6 / 2.7 represents the version of Python (2.4 / 2.6 / 2.7) that is supported.
Zenoss 2.x uses Python 2.4 - hence you need the Zenpack with 2.4 in its name.
Zenoss 3.x uses Python 2.6.
Zenoss 4.x uses Python 2.7
Be aware that the ZenPack naming is only a convention - folk do not have to include the Python version as part of its name. The ***BLOCKED*** by --allow-hosts message is usually a sure sign of the wring version though.
Cheers,
Jane