Issue targeting pages when using the Jigoshop plugin

I’m using the Jigoshop wordpress plugin, which I think is quite amazing, but a function of the plugin it to create it’s own pages.

The navigation on my site is using sprites, so I had to target the active states through PHP.

<?php
if ( is_page('outside') ) { $current1 = 'outside a'; }
elseif  ( is_page('shop') ) { $current2 = 'store a'; }
elseif  ( is_page('social') ) { $current3 = 'social a'; }
elseif  ( is_page('contact') ) { $current4 = 'contact a'; }
?>

<style type="text/css">
#menu ul#navigation li#<?php echo $current1; ?> {
	background:url(https://asvpart.com/new/wp-content/themes/Widescreen/images/outside.png)  0px -94px !important;
}

#menu ul#navigation li#<?php echo $current2; ?> {
	background:url(https://asvpart.com/new/wp-content/themes/Widescreen/images/store.png) 0px -94px !important;
}

#menu ul#navigation li#<?php echo $current3; ?> {
	background:url(https://asvpart.com/new/wp-content/themes/Widescreen/images/social.png)  0px -94px !important;
}

#menu ul#navigation li#<?php echo $current4; ?> {
	background:url(https://asvpart.com/new/wp-content/themes/Widescreen/images/contact.png)  0px -94px !important;
}

</style>

But with the plugin, I can not target the page “shop” to show the active state like the other pages. I can’t seem to figure out how to target that specific page in any way to get it to work properly.

Here is the site: https://asvpart.com/new/shop