Swapping SIM cards while overseas, problems on return?

I brought my Verizon iPhone 5 on vacation with me to Iceland. While there, i purchased a local prepaid SIM from a local carrier, Siminn. Once I landed, I immediately picked up Vodafone, as expected on a Verizon SIM. I turned off roaming data and proceeded to grab the prepaid card. Once installed, I picked up Siminn's network with no issue, voice and data worked flawlessly with no need to edit settings or anything. While there, I made some voice calls, iMessaged, played words with friends and also facetimed a few times for a total of about 2 GB of data over the week. While midflight home, I swapped back to my Verizon card (without rebooting or shutting down the phone first) but then shut it down for the remainder of the flight. Upon landing, I turned the phone on and picked up 3G instead of LTE. I did a hard reboot, it then picked up LTE just fine. SMS worked perfect, as did data and phone calls. This is where the problems started. I noticed I wasnt getting iMessages, they were coming through as SMS only. I checked iMessage and Facetime, they were hung as "waiting for activation". I tried to toggle them on and off, reboot, hard reboot, turn cell data on and off, log out and back into itunes and icloud, reset network and all settings.....everything. I also scoured google and found tons of threads on different forums, most covering iMessage activation issues with only a few centered around people who swapped SIM cards as the trigger. I was also getting errors stating "to use push notifications, sync to itunes" upon opening words with friends again once stateside. I tried syncing to itunes with no fix for that or the iMessage error. Most of the threads online went unanswered, with the people having no choice but to restore...which is what I ended up doing and now everything is working again.

My question is for those that travel overseas and switch SIM cards back and forth, have you ever encountered this? Did swapping networks cause your iMessage to lock up upon inserting your original SIM? Any fix?