I had a long, and mysterious, problem where trying to execute SVN commands on a Windows machine over HTTP would execute normally, whereas over HTTPS they would be extremely slow, but only for particular repositories:

svn info : 14 seconds
svn info : 14 seconds
svn info : 7 seconds
svn info : 37 seconds

This would only occur while I was at Massey, and only while I was at my machine. I asked the Google Code side and they assured me it was not a problem on their side.

Eventually, a system administrator came to help me solve the problem. Using Process Monitor, we kept a trace of svn.exe and tried to debug how it worked.

It turned out there was a major delay when trying to execute something through cryptnet.dll. After disabling cryptnet.dll (and allowing Windows to complain), the problem vanished.

Some researching indicated this problem had occurred before: cryptnet.dll was timing out because the machine was not connected to the Internet.

We have to use a proxy in order to use the Internet at Massey. I went into my Internet Connection settings for Windows, and saw that the proxy was being resolved to a script, rather than an actual proxy address. I switched it to a proxy manually, and the problem has gone! Hooray!