WordPress in HTML mode adding unwanted line breaks and paragraph tags

I am using WordPress for an ecommerce website paired with the shopping cart from Secure Net Shop. I am structuring the product pages with the cart code using HTML. When I paste the HTML into the WordPress page from Coda, WordPress adds line breaks and paragraph tags where I don’t intend there to be any.

I have line breaks in the code just for ease of editing and to create clean looking code. I really don’t want to remove them all, the code would be a mess to edit. Is there a solution for this?

For example, if I paste this into my WordPress page (again, visual editor is OFF):

<li><strong class="pr">Price</strong> $17.00</li>
	<li>
		<label for="size">Choose Size</label><br />
		<select name="option1|Size">
		<option value="novalue" select>- Please Select -</option>
		<option value="XS/Newborn">XS/Newborn</option>
		<option value="Small|1.00">Small - Add $1.00</option>
		<option value="Medium|2.00">Medium - Add $2.00</option>
		<option value="Medium Long|3.00">Medium Long - Add $3.00</option>
		<option value="Large|4.00">Large - Add $4.00</option>
		<option value="Extra Large|6.00">Extra Large - Add $6.00</option>
		</select>
	</li>

And then publish, I get warnings via my TIDY HTML Plugin as WordPress has turned the code into this:

<li><strong class="pr">Price</strong> $17.00</li>
<li>
		<label for="size">Choose Size</label></p>
<select name="option1|Size">
		<option value="novalue" select>- Please Select -</option><br />

		<option value="XS/Newborn">XS/Newborn</option><br />
		<option value="Small|1.00">Small - Add $1.00</option><br />
		<option value="Medium|2.00">Medium - Add $2.00</option><br />
		<option value="Medium Long|3.00">Medium Long - Add $3.00</option><br />
		<option value="Large|4.00">Large - Add $4.00</option><br />
		<option value="Extra Large|6.00">Extra Large - Add $6.00</option><br />

		</select>
</li>

See all those line break tags after the closing option tags? It’s kind of odd, because it doesn’t add them after everything.