We don't really know what is causing the slowdown for bookman. Several months ago, we had him run a debug build, and this is what we found:
The majority of the time is spent in calls to HttpSendRequest [1] and InternetReadFile [2] (standard Windows Internet APIs). Those calls are taking up to 4 seconds on your PC, vs. 200 milliseconds or less on our tests machines (1.5MB DSL connection). I don't believe there's anything we can do to make those calls to go any faster. About the only explanation I can think of (other than slow internet connection or slow server response, which don't seem to be the case if connectivity to that site is not slow in general) is something between UR and the server that is slowing the execution of these calls down (maybe some proxy, anti-virus, spyware, and/or other security software).
[1]
http://msdn2.microsoft.com/en-us/library/aa384247.aspx
[2]
http://msdn2.microsoft.com/en-us/library/aa385103.aspx