Can't save settings, view JS codes and very slow at loading (no replies)

I had just installed Piwik (latest stable release). The configuration went well without any errors. Database is created. I've added one website and when I tried to update some settings, the "Save" button would not work, as well as Edit button near the website's name on the "Websites" page. Here is what I got in the server's error log:

2014-02-27 19:07:37: (mod_fastcgi.c.2711) FastCGI-stderr: PHP Fatal error:  Maximum execution time of 30 seconds exceeded in /var/www/***.com/piwik/vendor/tedivm/jshrink/src/JShrink/Minifier.php on line 274
PHP Stack trace:
PHP   1. {main}() /var/www/***.com/piwik/index.php:0
PHP   2. Piwik\FrontController->dispatch() /var/www/***.com/piwik/index.php:62
PHP   3. call_user_func_array() /var/www/***.com/piwik/core/FrontController.php:117
PHP   4. Piwik\Plugins\Proxy\Controller->getCoreJs() /var/www/***.com/piwik/core/FrontController.php:0
PHP   5. Piwik\AssetManager->getMergedCoreJavaScript() /var/www/***.com/piwik/plugins/Proxy/Controller.php:51
PHP   6. Piwik\AssetManager->getMergedJavascript() /var/www/***.com/piwik/core/AssetManager.php:185
PHP   7. Piwik\AssetManager\UIAssetMerger->generateFile() /var/www/***.com/piwik/core/AssetManager.php:290
PHP   8. Piwik\AssetManager\UIAssetMerger\JScriptUIAssetMerger->getMergedAssets() /var/www/***.com/piwik/core/AssetManager/UIAssetMerger.php:56
PHP   9. Piwik\AssetManager\UIAssetMerger->getConcatenatedAssets() /var/www/***.com/piwik/core/AssetManager/UIAssetMerger/JScriptUIAssetMerger.php:42
PHP  10. Piwik\AssetManager\UIAssetMerger->concatenateAssets() /var/www/***.com/piwik/core/AssetManager/UIAssetMerger.php:101
PHP  11. Piwik\AssetManager\UIAssetMerger\JScriptUIAssetMerger->processFileContent() /var/www/***.com/piwik/core/AssetManager/UIAssetMerger.php:113
PHP  12. Piwik\AssetManager\UIAssetMinifier->minifyJs() /var/www/***.com/piwik/core/AssetManager/UIAssetMerger/JScriptUIAssetMerger.php:87
PHP  13. JShrink\Minifier::minify() /var/www/***.com/piwik/core/AssetManager/UIAssetMinifier.php:59
PHP  14. JShrink\Minifier->breakdownScript() /var/www/***.com/piwik/vendor/tedivm/jshrink/src/JShrink/Minifier.php:134
PHP  15. JShrink\Minifier->getReal() /var/www/***.com/piwik/vendor/tedivm/jshrink/src/JShrink/Minifier.php:253
PHP  16. JShrink\Minifier->getChar() /var/www/***.com/piwik/vendor/tedivm/jshrink/src/JShrink/Minifier.php:300

As you can see, the JSMinifier library fails. Some pages work just fine, while others are broken.