Actually based on your other post, it sounds like you're seeing a timeout - which is very different from my tests (wasn't anywhere near a timeout). Is it possible for me to get admin CP and FTP access to this? It's hard to debug when each rebuild step only takes 2 seconds locally. I have one possible guess of source, but I don't think that should be fatal.
This is on my local so I can't give out any details for it. I don't see it being a timeout issue as I set all the settings (memory, timeout, etc etc) really really high to try and avoid any of those sorts of issues. I started it up again before 7pm and it's only done 19,000 so far (19,000 in over 5 hours). It seems to be very much stop and start.
It's showing that error (An error occurred or the request was stopped) a lot of the time (I think it's on each jump) and occassionally showing where it's up to (presumably after it's resubmitted itself several times). So it is going through at the moment just taking absolutely ages due to that error. At one point I was presented with a button to continue and did so but that's the only time I've seen that appear. The rest of the time it's just forcing itself along at snail pace.
Well left it going over night, when I checked it this morning it had completely stopped (with that error) wasn't loading or anything so it looks like it had given up submitting itself. Carried it on again and then it took a couple more hours before finishing.