Using the quicktag button for OL produces <br> tags after all but the last </li> tag. This is with auto-P on by the way, just in case that's part of the solution.
This is what I have in a blog post:
<ul>
<li>Unordered Lists suck to make.</li>
<li>They are not friendly.</li>
<li>But they can be styled!</li>
</ul>
<ol>
<li>Ordered Lists suck to make.</li>
<li>They are not friendly.</li>
<li>But they can be styled!</li>
</ol>
Viewing the source reveals this:
<ul>
<li>Unordered Lists suck to make.</li>
<li>They are not friendly.</li>
<li>But they can be styled!</li>
</ul>
<ol>
<li>Ordered Lists suck to make.</li><br>
<li>They are not friendly.</li><br>
<li>But they can be styled!</li>
</ol>
BTW I can make it work properly by putting my everything for the ordered list on one line in the blog post. Like this:
<ol><li>Ordered Lists suck to make.</li><li>They are not friendly.</li><li>But they can be styled!</li></ol>
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Unrelated: why would b2evolution produce <br> when it should be <br />?
Crack open auto-p and remove the ol from this bit ( approx line 40 ) and see if that cures your problem :-
The plugin actually adds <br /> ?
¥