I've experienced the same error in Jaunty Beta (both an upgrade from Intrepid and a fresh install). Removing packagekit gets rid of the error.
The error would present using Update Manager to "check" for updates, or when "reloading" Synaptic - (after reloading Synaptic and clicking Close on the error window Synaptic would also close).
In either instance the updates would be found and display properly for download/installation.
I've experienced the same error in Jaunty Beta (both an upgrade from Intrepid and a fresh install). Removing packagekit gets rid of the error.
The error would present using Update Manager to "check" for updates, or when "reloading" Synaptic - (after reloading Synaptic and clicking Close on the error window Synaptic would also close).
In either instance the updates would be found and display properly for download/ installation.
Apt is not effected.