Getting StaticLoggerBinder.SINGLETON issue on slf4j older than 1.5.6

According to slf4j FAQ: this IllegalAccessError exceptions should occur only on versions 1.5.5 and earlier, because on 1.5.6 and later the SINGLETON field has been marked as private access.

But i'm getting this error on slf4j 1.5.3!

Caused by: java.lang.IllegalAccessError: tried to access field org.slf4j.impl.StaticLoggerBinder.SINGLETON from class org.slf4j.LoggerFactory at org.slf4j.LoggerFactory.(LoggerFactory.java:60)

Checked the deps:

mvn dependency:tree -Dverbose -Dincludes=org.slf4j [dependency:tree {execution: default-cli}] ma.tt.project:batch-ref-pr:jar:1.0 - org.slf4j:slf4j-log4j12:jar:1.5.3:compile - org.slf4j:slf4j-api:jar:1.5.3:compile

Running this spring batch through a Test or a Main class gives the same error.