Template caching problem

[eluser]Unknown[/eluser]
Hi,

I've enabled template caching in my website and when I browse for the second time to the same page it renders an empty page with some sort of cacheID: {739514fbc8a36b7af52aa74db2d4f5ed895018882}

Is there some setting that i'm missing?
The user guide isn't very specific on this item:
https://ellislab.com/expressionengine/us...ching.html

Thx