Scott Hanselman and Clemens ran into a nasty dasBlog 1.6 bug. Basically it was possible for your entry cache to get corrupted (not your entries). Thanks to Erv Walter for quickly investigating and fixing the problem.
I have uploaded a hotfix for folks that are running 1.6. It's a single DLL that you drop into your /bin folder. I have also upgraded all the MSI installers and .zip downloads on the workspace. You can download all the releases here.