Around the time my View Source stopped working, I had a run-in with a pesky web site that spawned a plethora of unwanted web browsers. I thought one of those intrusions might have corrupted my browser, so trying to fix it, I installed the Internet Explorer 5.01 Service Pack . That did not work. So, I looked at Microsoft's Knowledge Base to find some help. For each link, I summarized their solution.
Notepad needs to be installed.
The path for TMP environment variable is invalid. Need change permissions for Cookies folder when in NTFS partition. It takes the source from the Temporary Internet Files folder to another temporary folder. Refer to the link above for more information about this. So, in conclusion, I am not sure why clearing the cache helped, but it might have to do with the Temporary Internet Files folder having too much in it.