Recommended Tests

Also defrag. Restart your modem. Is it grounded OK, your system. Maybe something came loose.  Have you tried ccleaner? 

OK by clear cache what did you mean precisely?  What is your method?

Also has it been raining in the last week? Maybe a wet sat horn. It might have taken on water. Just poking through some old things I have gone through.

And your response to modem restartng?

Also try
start*all programs*accessories*system tools*Disk cleanup. That might help. 

I had this problem on the same service lvl and the same satt. you are on. I am on a wired network and I read in the forums that on a network it is easiest to run a hub and not a router if you dont mind running wires. I was already on a wired network run through a router so instead of assigning IP addresses through the router manually I just went to Wal-Mart and bought a $30 5 port hub and hooked it up and bingo , almost all pages load the first time through the gate now.

Also I agree that I don't understand why you have 4 ground blocks but I did have trouble with the transmit side of my ground block burning up which turned out to be water in the underground conduit causing it bu at any rate it didn't affect my page loads but it did slow my upload speeds way down before it would finally just lose connection after a while. I went through 4 ground blocks before I discovered it wasnt moisture getting in around the connections but instead water getting into the coax under ground.