Bug in reporting engine

Ok, I did some research about my reported bug in the report engine:

It occurs, if I select more than one content for a row or column of one 
attribute type for adding.

If I sourround the following lines in AttributeValue.setOptionId(Integer 
optionId) with a try and catch the error disappears:

Module module = getIssue().getModule();
IssueType issueType = getIssue().getIssueType();

It seems like the method getIssue returns null during the second call. 
What is this method for in this context? Is my workarround a fix? I 
would be happy if everything works again as in older days.

cheers
Johannes