Webcache is part of WinINET and is loaded before IE (as other WinINET. To stop the caching you need to tell WinINET to stop caching.
Credit to http://www.tenforums.com/general-support/37841-disable-webcachev01-dat.html
First, stop the following task in task scheduler: Microsoft > Windows > Wininet
Second step is to delete the dcom
REGEDIT search for this GUID:{3EB3C877-1F16-487C-9050-104DBCD66683}
Delete this GUID
You will have to change the ownership to your user to be able to delete this key.
Not pretty but it seems IE is piggybacking WinINET