Twitter doesn't work anymore. They depreciated the API. So you will have to turn off Twitter for now until I can get a new release out implementing a new usage.
Your button display issues are due to the below CSS conflicting.
IN: plugins/system/jch_optimize/cache/jscss.php?f=32eceebcebbaf79e8ef97f555385fa92-cache-plg_jch_optimize-f2dd816bbb24597922ac0b5e7431438a&type=css&gz=gz&d=30
ON: Line 3
Code:
.component-content .login + div ul li a:hover, #login-form a:hover {
background-position: 2px -272px;
}
IN: plugins/system/jch_optimize/cache/jscss.php?f=32eceebcebbaf79e8ef97f555385fa92-cache-plg_jch_optimize-f2dd816bbb24597922ac0b5e7431438a&type=css&gz=gz&d=30
ON: Line 4
Code:
.component-content .login + div ul li a, #login-form a, .component-content .items-more ol li a {
background-image: url(/templates/rt_kirigami/images/light/arrows.png);
}
IN: plugins/system/jch_optimize/cache/jscss.php?f=32eceebcebbaf79e8ef97f555385fa92-cache-plg_jch_optimize-f2dd816bbb24597922ac0b5e7431438a&type=css&gz=gz&d=30
ON: Line 3
Code:
.component-content .login + div ul li a, #login-form a {
padding: 4px 0 4px 15px;
line-height: 100%;
font-weight: normal;
font-size: 100%;
display: inline-block;
background-repeat: no-repeat;
background-position: 2px -65px;
}
You're using some sort of CSS compression + caching so I can't provide you with the actual locations. You can see the conflicting CSS by right clicking and inspecting the buttons in Chrome or Firebug for Firefox.