WordPress tinymce issue in article posting
Try this plugin - http://wordpress.ckeditor.com/. It replaces tinymce and many people find it more 'user friendly'. It has a 'Source' mode that seems to behave better than the HTML mode of tinymce.
You should debug your js-code using firebug.
Probably TinyMCE cannot initialize correctly, because of an JS error occuring earlier (in your js code or in wordpress plugin, i.e. Secure WordPress).
Check this, might help: http://wordpress.org/support/topic/uncaught-referenceerror-switcheditors-is-not-defined
The first thing you can try is go to Users > Your Profile, disable visual editor while editing, save the settings and then uncheck that box and save settings again.
After that, check if tinyMCE functions properly, otherwise, try to disable your plugins one by one to find out which plugin is causing the jQuery conflict.