The WDTV Live Hub Online Theme database is most probably no longer maintained since the WDTV Live Hub is now a Legacy Product.
Legacy Product Definition: legacy products are those that have become outdated, yet may or may not still be supported
If you want Themes, then download them here.
99.9% of SMP Themes will work on the Live Hub and Vice-Versa
There’s some online themes here you can manually download (Thanks KAD) … remember these are OLD themes and have not been updated in a long time
http://community.wd.com/t5/WD-TV-Themes/OSDModHub/m-p/723196/highlight/true#M14956
