Someone else was getting in requests between yours causing the port numbers to increase.
You had to accommodate for it in your script, if you received a number higher than the expected diff then you needed to keep sending the same request till you where sure they hit concurrently.
Basically the time to crack got longer the more people who were trying to crack it, it became an optimisation race in the end about who could get the requests in faster/closer together
I ended up finishing #65 due to not wanting to rewrite my slow python script. It took upwards of an hour to get a single chunk because of the load
I was running my script at about the same time as you then (multithreaded python with url2lib) - around 70 people had finished. I was obviously too impatient.
You had to accommodate for it in your script, if you received a number higher than the expected diff then you needed to keep sending the same request till you where sure they hit concurrently.
Basically the time to crack got longer the more people who were trying to crack it, it became an optimisation race in the end about who could get the requests in faster/closer together
I ended up finishing #65 due to not wanting to rewrite my slow python script. It took upwards of an hour to get a single chunk because of the load