Is rpool calc earnings wrong?

Hello everybody,

today I discovered a mystery I can not explain but somebody here can may help me. I mining since some days on rpool. Now today I checked my earnings like every day and determined I’m loosing XMPs between two blocks. How can that?
First I checked my earnings here and my account was by 0.08009161. But just an block later my account was only by 0.06192997.
My understanding is, the first value in the list beside your wallet ID is the value of XMP which you mined on this block, mostly it is strike through.
The second entry is than the value which you earned overall and will payed out once you get a balance of at least 0.3XPM.
Am I right? But why decreases my value than?

Any help would be appreciated.