First of all im going to say i do not know if this is a problem for only 512mb devices. Its not a massive problem but it is a problem nonetheless and there is a temporary fix. And after trying it for the fifth time im going to say it is definitely a bug.
If you put in about 6 apps make them all large tiles (It doesnt need to be large tiles, it can be medium or small, so long the tiles make the page long enough) and then tap on the live folders repeatedly for about three times or more rapidly, the apps will completely disappear from the start screen, now this is not a big deal.
But the only way you can make them appear again is to RESTART your phone OR if you are lucky 1 app will just randomly appear, while the rest will still remain to be unseen.
I tried it on two different folders.
Phone - Lumia 620 on dev preview.
If you have the time please try it out and let me know if im wrong and its just happening to my phone.
If you put in about 6 apps make them all large tiles (It doesnt need to be large tiles, it can be medium or small, so long the tiles make the page long enough) and then tap on the live folders repeatedly for about three times or more rapidly, the apps will completely disappear from the start screen, now this is not a big deal.
But the only way you can make them appear again is to RESTART your phone OR if you are lucky 1 app will just randomly appear, while the rest will still remain to be unseen.
I tried it on two different folders.
Phone - Lumia 620 on dev preview.
If you have the time please try it out and let me know if im wrong and its just happening to my phone.