I had a related problem and after a day of messing with my Windows and Java security settings, I called WD support at 1 800 275 4932. The rep said they were working on a fix for the Java 7.0.51 incompatibility, and recommended uninstalling it., and to download and install Java 7 Update 45. This worked, albeit the Java warning still pops up.
I have very slow remote downloads from the WD Mycloud server (2.5 minutes for 37 Mb) on my Vista laptop.
My iPad downloads the same file (on the same wi-fi) in 7 seconds.