SlideDeck 2 is a fairly complex plugin internally and can utilize a fairly large amount of memory per request. Normally this is not an issue, but sometimes you will need to increase available memory limit that PHP is allowed to use. You will want to increase PHP's memory limit if you are running into an error in your error log that looks like:
Fatal error: Out of memory (allocated 32016932) (tried to allocate 25152 bytes)
Method 1: Modify wp-config.php
WordPress has this method of increasing your web site's memory limit pretty well documented on their Codex. Check out what to modify at http://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP
Method 2: Modify PHP settings directly
If you cannot update your upload limitations with Method 1, please ask your web host to update your domain's PHP settings or how you can update your domain's PHP settings:
memory_limit = 128M
Your web host may be configured that you can add these lines in a php.ini file in your website's root folder or even use the php_value directive in your website's .htaccess file. Web host configurations vary, so you will need to ask your host about where they would like you to put these settings.