If you type the following line in php-mode (version 1.5.0):
// $foo->bar->foo->bar ();
The first "bar" and second "foo" appear in the font-lock-variable-name-face (yellow).
The second "bar" appears in the "default" face (white).
The rest of the line appears in font-lock-comment-face (red(?) by default, cyan due to customization on my system).
The whole line should appear in font-lock-comment-face. The same thing happens with multi-line comments. It is very distracting to have wrong colored words inside of commented out lines of code.