[Plugin: Contact Form 7] class: attribute BUG

There has been an isolated issue when adding the class: attribute. When it’s applied, the HTML tag on the website showed as:

[text* class:classname your-name 29/80 akismet:author "Your Name (required)"]
==turned to:==
<input name="class:classname" class="wpcf7 ... "

and when the (id:idname) attribute is applied, the following happened:

[text* id:idname your-name 29/80 akismet:author "Your Name (required)"]
==turned to:==
<input id="id:idname" class="wpcf7 ... " />

on the side note, I had text.php customized and changed the code of this line:

$html = '<input type="text" name="' . $name . '" value="' . esc_attr( $value ) . '"' . $atts . ' onblur="if (this.value == \'\') {this.value = \'' . esc_attr( $value ) . '\';}" onfocus="if (this.value == \'' . esc_attr( $value ) . '\') {this.value = \'\';}" />';

(That code is used so that a pre-entered text appears and disappears when you click on the text box.)