smart card no longer works

[Philip Jackson]

I have changed from Ubuntu 14.04 to a clean install of Ubuntu 16.04.1

This comes with gpg 1.4.20 and gpg2 2.1.11 as distro standards.

I brought into the new installation my keyfiles and config files and
trust.db

The private-keys-v1.d directory is populated with a series of
xyzzz123333.key files

The problem I have is that I cannot any longer decrypt files and this
manifests in 2 ways :

1. with gpg2 :    gpg2 --card-status
gpg: error getting version from 'scdaemon': No SmartCard daemon
gpg: OpenPGP card not available: No SmartCard daemon


2. with gpg :   gpg --card-status gives a lengthy and apparently good
output.

But the command  gpg -o output_file -d input_file.gpg

seems to be proceeding ok and puts up a pinentry window (anonymous)
asking for my pin.
I enter the pin (and I have double checked that it is correct) and get
It's a real PITAa failure :

gpg: ccid_transceive failed: (0x1000a)
gpg: apdu_send_simple(0) failed: card I/O error
gpg: using subkey 0x79D467BFF5DF6C91 instead of primary key
0x26BD500A23543A63
gpg: encrypted with 2048-bit RSA key, ID 0x79D467BFF5DF6C91, created
2014-10-28
      "Philip Jackson (Jan 2013 +) <philip.jackson at nordnet.fr>"
gpg: public key decryption failed: general error
gpg: decryption failed: secret key not available

Its a real PITA that a simple clean installation of an OS won't give a
working smartcard operation. It looks like the whole smartcard thing is
a little lacking in robustness.

[evidently, I can no longer sign emails with enigmail either]

So if someone could indicate where to start looking for the problems
with gpg2 and gpg, I'd be very grateful.
Thanks,

Philip