I have been using v1.9 on a Vista Ultimate system and everything worked fine until a search forced me to upgrade to v1.9.7
With 1.9.7 installed, the search returned a firewall error. I allowed Usenet Explorer in Windows firewall but still search returned firewall error. What's worse, the program would not download any files, giving me a question mark on everything.
I reinstalled v1.9 again and everything works but the search engine, which now requires v1.9.7
v1.9.7 and firewall
probably you need to delete and reallow ue in firewall, because the executable changed maybe the firewall doesn't recognize it any more as the file which you allowed to internet access (e.g. if something modified the file the firewall is supposed to detect it and the result is the same, the file is different from previous version).