The PHP syntax-highlighter does not support the following (valid) construct:

if ($foo) {
  print "${bar}";
}

Reason is, that NetBeans interprets the curly braces inside the string literal as the closing bracket of the if-clause.
However the following works fine:

if ($foo) {
  print "{$bar}";
}

Both code examples are equal. The highlighter should treat the first code fragment in the same way as the second.