dont use this ports for end users.
First the asa working as firewall alsoالموضوع الأصلى من هنا: منتديات سيسكو التعليمية | كن بين الخبراء ! http://www.ciscovb.com/vb/t1408.html#post10831
so connec new switch 48 ports 3750 series and connec the end users to this switch;
its better to use the port with spf LHC for single mode fiber for more performance
but you have problem ? how many routers you have ! as I saw you have only one asa that is mean no redundancy ! you fucked up ! have fun