Many of them got blocked, including the entire previous top 20. Wrong program versions and/or wrong ways to run them.
The accepted versions of the benchmarks in hwbot can be found from the first forum posts of the ranking threads. With the pifast package comes a bat-file and the program should be run with that.
Users updating online must search the instructions from some other team's forums for now.
Sorry for the confusion. We are planning on making some hwbot benchmarking instructions to website later.
"What is not surrounded by uncertainty cannot be the truth." (Feynmanism)