It is a mess....
Just finished the math again and found that blocks 21305, 21306 and 21307 are indeed deleted from the unconfirmed total but not added to the confirmed rewards.
Next block to be confirmed is 21320; I'll watch to see if block 21308 is then deleted from my unconfirmed total.
Edit: Next round to be confirmed was 21327 not 21320. -- never mind the edit.
When round 21320 confirmed, no changes were made in unconfirmed, confirmed or total rewards. I'll have to see if new block causes any problems.
Bingo! Round 21328 came in and the reward for round 21308 was deleted from the unconfirmed and total tallies. The confirmed tally didn't change.
So if I want to calculate my true confirmed + unconfirmed right now, which round do I need to start with? Which round was the last one to correctly post to confirmed?
I'm not sure what 'Which round was the last one to correctly post to confirmed?' means to you. All the rounds seem to post confirmed correctly, they just don't add anything to the confirmed tally, but they do remain in the unconfirmed tally for some period of time.
I became aware of the confirmed tally being frozen from a post by another user here. I recorded the unconfirmed, confirmed and total tally on my account page and after round 21316 confirmed, I went to my account page and saw that the unconfirmed and total tallies had not changed, nor had the confirmed tally. We won a couple of blocks shorty thereafter and then I saw that my unconfirmed and total tallies had dropped in value.
The first round I saw dropped was 21304 and this was the sequence:
We won a round and my unconfirmed and total tallies were reduced by my reward for block 21304.
After 15 minutes or so, the new block's reward was added to my unconfirmed and total tallies.
This sequence has now happened with every round since:
21304 dropped and 21324 added
21305 dropped and 21325 added
21306 dropped and 21326 added
21307 dropped and 31227 added
21308 dropped and 31228 added
21309 dropped and 31229 added
All the while the confirmed reward has been frozen.