Internet Explorer 8 beta participants today received a surprising e-mail about 'IE8 Partner Build' released to the IE8 Technical Beta to test and find issues. This build represents a preview of IE8's progress and is best used to verify issues fixed since releasing Beta 2. While Microsoft believes it to be of adequate quality for you to use, is not as extensively tested as a milestone build, so it is not meant for the general public but only for testing purposes.
Microsoft is not providing any support for this build and henceforth just like in transition from Beta 1 to Beta 2, if you feel that Microsoft have resolved misfiled your bug, please re-activate the bug. You can do so here.
As Microsoft is getting closer to the release of IE8, its looking for the most impactful bugs to be fixed before the final release.