App authentication on disconnected devices

[rfm2113]

I had attempted to create iPod Touch-like devices with my old phones, namely Motorola Defy(MIUI) and LG P-999(CM7), by either deleting the appropriate apks or by keeping the device in airplane mode. Everything works fine for a while, then after a few days/weeks, apps will stop working, insisting on connecting to the internet to authenticate. Once this is done, the apps will work again temporarily, but for a much shorter time before needing to re-authenticate. Some apps, like Pocket League Story, periodically re-auth like this even on my active device, but every app does it on my Defy and G2X. I don't notice this ever happening on my CM7 Nook Color.

Is there any way to prevent this from happening? It just seems odd to me that it happens on the two phones, but not on the reader. Is this a build.prop thing? A newer development that didn't exist when I installed the apps I use on my nook, but did when I converted the Defy and G2X? I was trying to use the G2X as a media player, keeping my music on a 32GB microSDHC so I didn't have to clog up my Galaxy Nexus with music, but PowerAMP crashed so often that I had to abandon the idea. I gave the Defy to my girlfriend to use for apps and whatnot as an introduction to Android, but she spends more time waiting to authenticate than she does using it. Frustrating.

Any ideas? I'm open to tinkering.

Thanks in advance!