/tmp is tmpfs by default nowadays, which makes it a bad default for the cache dir -- it gets cleared on reboots and may thus result in . /var/cache/inadyn(-mt) would be a better choice, see for example how ez-ipupdate does it.
I have applied a patch on the new package inadyn-mt-2.24.38-1.fc21 which should be available on rawhide. Unfortunatey, dyndsn.com has discontinued his free services, so I could not test thiw new package. So if may be nice, if you can take a shout test with this package an inform me about the test results.
inadyn-mt-2.24.38-2.fc20 has been submitted as an update for Fedora 20. https://admin.fedoraproject.org/updates/inadyn-mt-2.24.38-2.fc20
Package inadyn-mt-2.24.38-2.fc20: * should fix your issue, * was pushed to the Fedora 20 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing inadyn-mt-2.24.38-2.fc20' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2014-5892/inadyn-mt-2.24.38-2.fc20 then log in and leave karma (feedback).
inadyn-mt-2.24.38-2.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.