[CentOS] CentOS5: Can't Access the Web Using Firefox Web Browser

Many times (not always) when I click on a URL in an email, the cursor 
(rotating arrow) lasts for 5-10 seconds, then nada. If I exit email to 
the  desktop,nether the tool-bar icon, nor the 
Applications->Internet->Firefox Web Browser route will get me unto the 
web although the cursor shows a rotating arrow for a few seconds. Some 
other task may be executing as the hard disk is working away. Yet,I can 
get into Email without waiting (higher priority interrupt?).

1. Shouldn't there be a way of re-assigning priorities to the interrupts?

2. If my request has to wait, why should it be dropped completely making 
me re-enter the request every 5 seconds?

Thanks  --  Bob T.