Just guessing cause I'm a novice at this.
Your products list:
<span><a href="/store/Products_Results.php">Products</a></span>
<ul class="level-1">
<li><a href="/store/Products_Search.php">Search</a></li>
<li><a href="/store/Products_Results.php?Search.x=0">Show All Products</a></li>
<li><a href="/store/Products_Results.php?Search_x=true&CategoryID=1">leashes</a></li>
<li><a href="/store/Products_Results.php?Search_x=true&CategoryID=4">accessories</a></li>
<li><a href="/store/Products_Results.php?Search_x=true&CategoryID=5">jewelry</a></li>
<li><a href="/store/Products_Results.php?Search_x=true&CategoryID=7">Sueriffic</a></li>
</ul>
My products list:
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=0">Show All Products</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=1">Hats</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=2">Tees</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=3">Hoodie-Pullover</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=4">Hoodie-Zip Up</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=5">Tools</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=6">Tack</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=7">Safety Equipment - Horse</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=8">Safety Equipment - Human</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=9">Youth Tee</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=10">Sweatshirt</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=11">Hoodie Tee</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=12">Polo Shirt</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=13">Mugs</a></li>
<li><a href="/intuHorsesPowerStore/Products_Results.php?Search=true&CategoryID=14">Greeting Cards</a></li>
</ul>
I think your "Search.x=0">Show All Products" followed by
"Search_x=true&CategoryID=" everywhere else may be the problem.
In mine it's Search=0 or Search=true
Again, I'm just guessing here.
Regarding your second question. Main.dwt.php is the template controlling those elements and common.css is where I made my changes.
My work in progress.
intuHorsesPowerStore/
Mick