Dave's Redistricting now supports Washington, DC and Puerto Rico. You'll need the new version (2.2.20). DC is supported with both 2010 and 2000 block groups. (There are no VTDs from the Census Bureau.) Puerto Rico has only 2010 block groups.
Also new is presidential data for Washington State and Utah, courtesy of roguemapper.
More about Silverlight 5 issues below the fold.
Some of you have reported the app failing to load large states, such as California or Texas. With the change to allow extra data sets, such as the Texas Voter Registration data (Version 2.2.18), all states use a little more memory. Texas uses additional memory for that extra data. With Silverlight 4, which is all that is required by the app, I have not been able to reproduce the problem. But with Silverlight 5 and IE9, I can reproduce it. It seems that with SL5, a little more memory is being consumed. I have reduced slightly the memory usage in the latest version (2.2.20), so for states other than Texas, the usage should be less than before 2.2.18.
I recommend (a) if you're not experiencing a problem, do nothing; (b) if you're seeing the problem and have Silverlight 5, go back to Silverlight 4 if you can; (c) don't upgrade to Silverlight 5 if you can avoid it. I have not tried on the Mac yet or on all the other browsers.
To go back to SL4, you'll need to uninstall SL5 first.