Edit page with form problem

Hi.
I’m trying to create a page with a form on my wordpress site.
If i add textareas to the editor it saves without problem, but if i return to continue editing it shows a completely uneditable page.
i am not using any html editor, just plain textarea.
Test form could be:

<form method = "post">
Name: <input type="text" name="name" />
Comment: <textarea name="comment"></textarea>
</form>

This is just a simple form that shows the problem (mine has more fields) 😉
Thanks for your help.
🙂
Byron H.
ps. I’m working with formpress plugin to create forms (i’m doing it many changes), but i need to create manually some forms in pages.