@xes and justmemory could be that it is a ssl problem which faces xes, but on justmemory's system it is not the case. So lets see where is the difference.

1. which cutube2 and which qyoutube version is installed?

could be that you need a version which is not in extras

2. which maemosec-certman-common-ca version is installed

certificate could be to old

3. which libqt4-network version is installed

could be that you need SNI-patch

4. which openssl version is installed

could be you need higher support of TLS version (cutube2 version in repository is fixed to TLS v1.0 same for qyoutube)
edit: or maybe it is libsoup or gnutls what freemangordon said