Modules will not stay enabled

Hello,

Here is a bit of a run-down of what went down.

There was a security update for the XML Site Map module. I had updated the module on my local development site, then pushed the new module files up to production via git. I ran the update process as normal and everything seemed to be okay. What I didn't know, however, is that during this process, a few of my other modules were disabled automatically. It caused a nightmare of a day, but that is not the point of this!

After I discovered that these modules had been disabled (various Ubercart modules), I tried to simply enable them through the admin panel as normal, but no dice. The page would simply refresh and would not save my configuration. I then went into the database, set those modules enable field to 1, and they still were not enabled. I had to then go back into the database, enable them, then clear my cache. After that, the modules are enabled and working as expected.

My issue is now is anytime I make a change on the modules page, those few offending modules disable themselves again. Is this a registry or some sort of cache issue?

Some other information:

Memcached enabled
Apache 2.4+
PHP 5.5

Thank you in advance to anyone who replies!