configuring the html filter - not enough characters allowed to add all of the tags needed for the FCKeditor

Hoping that somebody can help me with this issue.

I am trying to configure the html filter in Drupal 6.2 (accessed via http://mysitename.com/admin/settings/filters, or via the admin > site config > input settings tab) for use with the FCKeditor module and I am unable to add all of tags that I would like to allow for a given input format. When I try to configure the format, the system won't let me enter more than 250-255 characters or so.

Created a new input format I named "contributorRTE," which I am planning on allowing for a particular role I set called "contributor". Clicked on the "configure" link and then on the "configure" tab, and then tried to add in all of the tags I want to add in the "Allowed HTML tags" box, but I am unable to add of the tags -- it appears that I can only add around 250 characters.

These are the tags I want to allow for this input format:

<a> <p> <span> <div> <h1> <h2> <h3> <h4> <h5> <h6> <img> <img /> <map> <area> <hr> <br> <br /> <ul> <ol> <li> <dl> <dt> <dd> <table> <tr> <td> <em> <b> <u> <i> <strong> <font> <del> <ins> <sub> <sup> <quote> <blockquote> <pre> <address> <code> <cite> <embed> <object> <strike> <caption>

Tried to copy and paste this into the "Allowed HTML tags" box but it gets cut off at the <embed> tag. Unable to type in any more characters.

This is probably a simple thing to fix somewhere in the site configuration..but I've tried a bunch of things and have searched for a couple of hours, so I thought I'd see if somebody could help.

Thanks so much.