Built-in suggestions come either from words already contained in the document, or from highlight words that are defined in the Configuration Properties > Highlight (1) tab. In the PHP case, keywords might come from HTML configuration, or even from JavaScript or VBScript. By default, all PHP and HTML keywords are lowercases. Did you import some other keywords or did you define keywords yourself? What kind of keywords eactly do you see uppcases? Scripting or PHP keywords? You might want to reset all configurations and see if you can see the difference.