I'm using the latest version of the eRepublik Stuff + script. I updated it even today. I'm using Mozilla Firefox 18.0.2. Other than this script, I have eRep Advanced installed and currencly in use. I also have eRepublik Stuff installed but I don't use it anymore. It is disabled.
If I leave a battle open between rounds I get IP blocked for a few minutes right after the new rounds starts and the tab automatically refreshes. If I activate auto energy recovery, it blocks me after a few minutes, despite the eRepublik page I'm in (battles, storage, profile, etc.). Both issues were recurrent with eRepublik Stuff as well.
I also get randomly IP blocked in random eRepublik pages without any battles open and without the auto energy recovery on.
A friend of mine has also told me that he gets IP blocked after uploading a new avatar and refreshing the page.
IP blocks here and there are reasonable due to multiple background page requests by script. If you have some other script instaled or PULSE extension disable it, or play with settings and configure them so you have minimal number of IP blocades.