This is an extremely bizarre problem, and I can't believe it myself. I've never seen anything quite like it in my 30 years of computing. It has me a little frightened. Please bear with me as I struggle to explain the situation as clearly as possible without becoming emotional.
My girlfriend's iMac running OS X connects to the Internet wirelessly via our shared 2wire modem (gateway, router, whatever). Recently she began using Google Chrome browser, and that's about the time trouble began. Now every time she quits from Chrome, the DSL modem resets itself.
There are several other clients connected to the modem, both wired and wireless. None of them exhibit the same symptom, but none of them run Chrome either. When the DSL modem resets it causes a momentary interruption of Internet connectivity while the modem reinitializes itself.
I couldn't even pin it down to the iMac+Chrome combination until I began logging the date and time of the disruptions. Sure enough, there it was. Every time she quits Chrome, the modem resets. I can reproduce it consistently myself. In fact, I did it again before posting this help request just to make absolutely certain that I'm not going mad.
I can not even put into words how infuriating this disruption has been. My girlfriend loves Chrome, so I don't want to tell her she can't use it.
Please help.
Edit
I found this help request from 2009 which seems very similar to my problem:
Google chrome constantly crashes my wifi
Extensions installed on Chrome:
- Amazon - disabled - says it adds an Amazon link to new tabs

- Google Mail Checker - enabled
- Last Pass - enabled
- Sudoku for Google Chrome - enabled -

- WeatherWindow Beta by Weather Bug - enabled -

I tried iChat, Safari, and Firefox. None of them cause the modem to reset.