Synaptic Package Manager error

[stevef]

I'd guess updating/upgrading is mostly done using a terminal or via 'Install Updates' and that Package Manager is mostly used for installing and removing applications.
Does Package Manager work ok on your system for installing and removing applications ?

But if i try to use the Synaptic Package Manager i get the error message. Suppose i'll have to live with that

It doesn't sound as though everything is working as you expect.
What exactly are you doing with Package Manager when you see these notifications ?