Wanted to add this so you have more data to work with. On 09/04 and again on 09/05 I voted on posts by @theouterlight. It was right after the 5 minute mark and the amount of curation was very small both times. The posts grew to curation of 30.45 and 41.60 respectively, yet shows 0 pending curation rewards for me. Yesterday I voted in at 6 minutes and that post is showing curation. All other posts I vote on that falls right after that 5 minute bar shows rewards, but I'm still not ruling out a possible glitch in the blockchain timer for some accounts. Hoping though it is some sort of communication glitch from the blockchain to your program though as they should have given me my largest curation rewards of the month, lol.

edited to add that the weight for both votes was 100% as shown as well on SteemWorld.