I'm using IDEA #7531 which bundles WebServicesPlugin 0.9 build 2. PluginUpdateNotifier found that WebServicesPlugin has a new version, but the version number is 0.9 build 1.
The strange thing is I don't have this problem at home, only at work. I tried to delete .IntelliJIdea70 folder but it didn't help.
And I'm using PluginUpdateNotifier 2.0.3