Fresh installation, started jenkins from command line (java -DJENKINS_HOME=C:\temp -jar jenkins.war), no other jobs defined or plugins installed.
Created 2 Freestyle jobs (A+B).
Start Job A with delay 1000 sec: http://localhost:8080/job/A/build?delay=1000sec.
Start Job B with no delay.
Job B should start immediately.
Job B waits until start of Job A.
This bug first occured in version 1.452, version 1.451 is ok.