issues with ghash?
anyone experiencing the same as well or am i totally wrong?

example.. 1 TH mining power i should be earning 0.02684 daily according to bitcoinwisdom with best conditions at current diff.  
past 3-4 days or so i'm making less than 0.012 per th.

previously when ghash was mining every 3rd or 4th block i would get close to expectations -20% to -25%

1) is this acceptable?  
2) if the total hash rate of ghash has dropped and my hashrate remains the same per block found, i should not have my overall earnings affected over time?

is my logic correct? where am i mistaken?
i have checked my miners and they are hashing at normal speed.