Many people would consider those broadband speeds as very good, considering that some would even think 2000 kbps was OK - all depends on type of connection and distance from exchange among other things.
What is your speed supposed to be according to your ISP?
I have recently upgraded my broadband to BT Infinity and am now getting constant speeds in excess of 37Mbps - before upgrading I thought my 1.9Mb was pretty good!
I don't use Ccleaner, but I thought Ccleaner cleared temp files! Or you could go to Tools and Internet Options in I.E. to clear temp files.