sonar credential issue while running jenkins build - sonarqube

Question

I am using Jenkins version 1.480.3 and Sonar version 3.4.1. I am executing Sonar analysis on my project using maven build option "sonar:sonar -PsonarJs" and below properties in jenkins:-
sonar.login=sonar
sonar.password=*****
sonar.host.connectTimeoutMs=300000
sonar.host.readTimeoutMs=600000
projectVersion=${projectVersion}
sonar.projectKey=abc
sonar.projectName=abc
sonar.projectVersion=${projectVersion}
sonar.sources=${MyPath)
sonar.branch=javascript
sonar.language=js
sonar.forceAnalysis=true
"sonar" is a local user created in Sonar.Upon firing the build in jenkins,sometimes my build fails with the following error:-
[ERROR] Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.0:sonar (default-cli) on project vos-generic: Can not execute Sonar: Not authorized. Please check the properties sonar.login and sonar.password.
This is an intermittent error, sometimes the build fails with this error and sometimes it is successful.
I tried to resolve this error by creating a new local user "sonar1" in Sonar and adding it to the administrative group but got the same error again.
Any help is appreciated.Thanks in advance.