Gmap will be shown correctly on the custom page with "Admin">"Pages">"Add Page". The reason is that contents of the custom page is shown as it is without being sanitized for security. On the other hand, posts are sanitized by HTMLawed just before being shown. HTMLawed does not allow "iframe" tag by default. Look at qa-include/qa-base.php::qa_sanitize_html(). Below thread will be useful.
http://www.question2answer.org/qa/38943
My CKEditor plugin is unnecessary. You will be able to deal with core hacking or overriding qa_sanitize_html() function.
- 8.1 Easy solution (for Q2A beginner)
- 8.2 Expert solution (for Q2A engineer / designer / etc)
Point:
//'elements' => '*+embed+object-form',
'elements' => '*+embed+object+iframe-form',
Caution:
If you allow iframe, your site will be vulnerable relatively. It is important that registered users are trustworthy people.