Hmm. It didn't so much swallow a fur ball as cough one up.
PS - the site is back up.
Yes.
They provided a new upgraded the client with a minimum CUDA driver version 25x.x and higher.
BUT the existing CUDA 2.3 is also still valid.
I have tested that this 2.3 app is still available: Linux_AMD64 is anyway
I am not sure why your machine has deferred to the 3.1 client unless your driver compatible with that version but there is a client-app compile problem.
e.g. the new client deos not defer back to the old client if the new client fails to work.
I can't recall ever seeing two client apps for the same base architecture on any project (regardless of GPU version).
They have managed it well so far.
But it is not surprising that they would run into a problem with this eventually.
Scan the project forums.
If anyone else is having the same problem I am sure we will hear more about it very soon.