"As you type" firefox spell checker doesn't work, but "as you type" spellchecker working on Chrome

Issue Summary

"As you type" firefox spell checker doesn't work, but "as you type" spellchecker working on Chrome

Hi,

When i create a page on my website with TinyTiny Mce module installed using Chrome, this browser underlines the errors when i am typing.

When i create a page on the same website using Firefox, the "as you type" spell checker doesn't work.

Do you have any idea how to enable it ? What is the difference between Chrome and Firefox when using the greatest TinyTiny Mce module ? Have you seen the "as you type" spellchecker working in Firefox with another Wysiwyg module ?

Thanks for help.