Low on space notification

[dirtysouth12]

Hey guys, I just had this message pop up earlier, I have read the other thread about the leak with HTC mail but I am not using HTC mail.

I have 6.34GB available space on my internal phone memory. And 686MB available space on my phone memory.

Not sure what has caused my phone to give me this notification??

 

[CharlesA03]

My phone randomly did this once (even though I had plenty available still).

I rebooted and it hasn't popped up since.