The last week or so, I've noticed that my Nexus 7 loses responsiveness after I've used it for a while and the battery is down around 20% I'm not sure if it's a battery issue or a memory issue although I've closed open apps without any noticeable positive effect.

I tend to think it's a memory issue because I can reboot it before it's recharged and that typically restores its responsiveness.

Anyone else run into this? It's more an irritant than anything else but it's a drawback to an otherwise perfect tablet that pretty much has been a really good experience