I made a list of all the countries that have the 'noflag' problem. It's easy to spot them in install_english.php by doing a text search for noflag.gif.
Anguilla, Brunei Darussalam, Bouvet Island, Belarus, Belize, Cocos Keeling Islands, Dem. Rep. Congo, Cote d Ivoire, Cape Verde, Christmas Island, Wesetern Sahara, Falkland Islands, Faroe Islands, French Guiana, Gibraltar, Guadaloupe, Equatorial Guinea, South Georgia and South Sandwich Islands, Guam, Heard and McDonald Islands, Israel, Jersey, Saint Kitts and Nevis, Cayman Islands, Libya, Mali, Northern Mariana Islands, Martinique, Montserrat, Mauritius, New Caledonia, Norfolk, Island, Nepal, Niue, French Polynesia, Saint Pierre and Miquelon, Pitcairn, Qatar, Reunion, Saint Helena, Svalbard and Jan Mayen Islands, San Marino, Sao Tome and Principe, El Salvador, Turks and Caicos Islands, French Southern Territories, Tokelau, East Timor, US Minor Outlying Islands, Saint Vincent and the Grenadines, Virgin Islands British, Wallis and Futuna Islands, Samoa, Mayotte.
Now here's what I DON'T get: I fixed the El Salvador link in the database as a test fix and even though that entry now correctly points to elsalvador.gif, I still see the flag on the stats page as noflag.gif. Weird. :/