Release fails with maven-javadoc-plugin 2.10

Hi all, I've started seeing failures when doing a release during this week.
The projects released just fine previously.
The release fails at the "perform" stage when it's doing "attach-javadocs".
Usually the error is something like this, the javadoc plugin fails with
dependencies:
[INFO] [ERROR] Failed to execute goal
org.apache.maven.plugins:maven-javadoc-plugin:2.10:jar (attach-javadocs) on
project MyProj: MavenReportException: Error while creating archive: [INFO]
[ERROR] Exit code: 1 -
E:\jenkins-work\release_MyProj-1.2\workspace\target\checkout\src\main\java\...\MyController.java:3:
package javax.portlet does not exist [INFO] [ERROR] import
javax.portlet.RenderRequest; [INFO] [ERROR] ^ [INFO] [ERROR]
E:\jenkins-work\release_aulis-Portlets-1.2\workspace\target\checkout\src\main\java\...\MyController.java:4:
package javax.portlet does not exist
A workaround is to skip the javadoc generation but it has to be configured
for each project. There are quite a number of those in my environment.. But
why does javadoc generation even need the dependencies?
Anyone else having the same problem?