After banging my head against the desk all morning wondering why making several of the changes recommended by Page Speed, my score wasn't changing despite clicking refresh analysis (about 10 times over a two hour period). When I looked closely, it wasn't registering any of the changes! I tried using the Page Speed tool for Chrome and discovered that my score had increased 12 points! The tool on the wordpress dashboard did finally update, but still shows a score 1 point lower than the Chrome plugin.
For whatever reason, the "refresh analysis" link on the Page Speed dashboard widget is not actually refreshing the analysis.