Additional information on Fresh installation on Debian stable - acli/ATutor GitHub Wiki
At step 4, squid reported the following:
1367510317.637 343 127.0.0.1 TCP_MISS/200 4373 POST http://atutor-test.gniw.ca/install/install.php - HIER_DIRECT/71.19.145.98 text/html 1367510317.763 184 127.0.0.1 TCP_CLIENT_REFRESH_MISS/200 9716 GET http://atutor-test.gniw.ca/install/stylesheet.css - HIER_DIRECT/71.19.145.98 text/css 1367510319.683 2104 127.0.0.1 TCP_CLIENT_REFRESH_MISS/200 632356 GET http://atutor-test.gniw.ca/jscripts/infusion/InfusionAll.js - HIER_DIRECT/71.19.145.98 application/x-javascript 1367510319.860 102 127.0.0.1 TCP_CLIENT_REFRESH_MISS/200 9716 GET http://atutor-test.gniw.ca/install/stylesheet.css - HIER_DIRECT/71.19.145.98 text/css 1367510319.861 102 127.0.0.1 TCP_CLIENT_REFRESH_MISS/200 340 GET http://atutor-test.gniw.ca/images/clr.gif - HIER_DIRECT/71.19.145.98 image/gif 1367510319.871 112 127.0.0.1 TCP_CLIENT_REFRESH_MISS/200 849 GET http://atutor-test.gniw.ca/images/check.gif - HIER_DIRECT/71.19.145.98 image/gif 1367510320.015 257 127.0.0.1 TCP_CLIENT_REFRESH_MISS/200 11080 GET http://atutor-test.gniw.ca/images/AT_Logo_1_sm.png - HIER_DIRECT/71.19.145.98 image/png
The Javascript console did not show anything suspicious.
Apparently, the installer was trying to connect directly to the ATutor server without going through proxies. This, of course, will always fail in some environments…