Inconsistent behavior with filtered tags

On a clean install of Drupal 6 beta 3, I added these tags to the Filtered HTML input format: <table> <thead> <tbody> <tr> <td>.

I created a page containing the following code before adding those tags to Filtered HTML:

<h3>Officers</h3>
<table border="1" style="border-collapse: collapse;">
    <thead>
        <tr>
            <td><strong>Position</strong></td>
            <td><strong>Name</strong></td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>President and Director</td>
            <td><a href="mailto:xx@yy.zz">Bubba President</a></td>
        </tr>
        <tr>
            <td>Treasurer</td>
            <td><a href="mailto:aa@bb.cc">Bubba Treasurer</a></td>
        </tr>
    </tbody>
</table>

The table tags are predictably stripped out of the rendered output since they are not in the Filtered HTML input filter.

Then I change the input filer to add the table-related tags listed above, edit the page, and save it without modifying it. The output remains filtered even though I changed the filter to allow the table.

Then if I edit the page again, add a space before the close quote in the <table> tag's style attribute, and save the page, I do get the correctly rendered text.

But it gets weirder. If I re-edit the page and remove that space--in effect, reverting to how it was originally--I get the original filtered page with no table tags!

What should be happening:

• If I re-save a page, even if I don't change its body, the new filter rules should always be applied.
• Manually making changes to a page's content that happens to revert it to an earlier version--one that happened to exist before the input filter's allowed tags field was changed--should not cause the rendered content to go to an invalid state.