Error Message:
System.BadImageFormatException: Could not load file or assembly 'BasicFrame.WebControls.BasicDatePicker' or one of its dependencies.
Likely cause:
dasBlog ships with the x86 assembly, and you're running x64 IIS with 64-bit worker processes.
Solution:
Replace the BasicDatePicker DLL in the /bin folder with the one from this archive.
http://www.basicdatepicker.com/download/BasicDatePicker_x64.zip via http://www.basicdatepicker.com/
Further reading:
Scott Hanselman has a nice, much more detailed writeup about this, which details a lot more information about IIS 7.0 and dasBlog.
http://www.hanselman.com/blog/32bitnessAnd64bitnessAndMigratingDasBlogOnIIS7AndASPNETUnderVista64.aspx
I'm still on IIS 6.0 - waiting for my Seagate ES.2 drives before putting the 2008 November CTP into production...