fetchmail_interval not honored?

[rainforest1155]

It is my understanding that the fetchmail_interval is in place so that fetchmail isn't polling repeatedly whenever the imap client polls for new mail or the user taps on the refresh button too often. In my 90-fetchmail_wakeup.conf, I do have:
fetchmail_interval = 120

However if I click on the refresh button in my imap client 2 times within a few seconds, fetchmail is called upon not just once but two times:
Feb 8 20:16:56 fetchmail[7409]: awakened by User defined signal 1
...
Feb 8 20:17:02 fetchmail[7409]: awakened by User defined signal 1
...

Initially I was still using version 2.1.0 of fetchmail_wakeup when I encountered the issue. Updating to 2.1.1 didn't change anything.

I'm using Dovecot 2.1.7-7 on Debian 7. I made sure to always restart the Dovecot service after making changes to the config.

Is there some part of the configuration that I might be overlooking?

Thanks,
Sebastian

[rainforest1155]

Today I tried it with debug enabled, however the built-in debug output didn't provide much insight. It was basically just giving me this message:
Mar 6 17:55:29 dovecot: imap(): Debug: fetchmail_wakeup: rate limit passed.

I tried adding some additional debug details in fetchmail_wakeup.c. In specific, after line 99 I added:
i_debug("fetchmail_wakeup: last_one.tv_sec: %lu - now.tv_sec: %lu - millisec_delta: %ld ", (long)last_one.tv_sec, (long)now.tv_sec, (long)millisec_delta);
which results in output like this:
Mar 6 17:54:56 dovecot: imap(): Debug: fetchmail_wakeup: last_one.tv_sec: 0 - now.tv_sec: 1394124896 - millisec_delta: -1739474924
Even on repeated fetches, the last_one variable always gets returned as 0. I'm not sure why that is, but somehow it appears to be the culprit.

So I figured it might not be set properly and so I added this debug line after line 101:
i_debug("fetchmail_wakeup: updating last_one.tv_sec: %lu",(long)last_one.tv_sec);
which results in debug output like this:
Mar 6 19:15:00 dovecot: imap(): Debug: fetchmail_wakeup: updating last_one.tv_sec: 1394129700

So the last_one variable seems to be updated. However, on subsequent runs of the fetches, it's somehow always 0. Could this be a problem with my dovecot config?
It kind of appears as if dovecot always exits the plugin and starts it up clean each time, which is why the last_one variable is always 0?!

By the way, the line numbers given are based on your current master branch.

Thanks for any assistance you can offer,
Sebastian

[nfp0]

I'm on Debian 8.2 with Dovecot 2.1.7-7 and fetchmail_wakeup 2.1.1 and I seem to have the same problem. Whatever I set fetchmail_interval to, it never gets honored. Omitting also does not honor the 60 seconds default.