Bug? I can't change administrator and subject of process dynamically

Question

See below. Are they bugs? How should I solve them?
Symptom 1:
In a process, I set administrator using expression, and subject using a variable.In the first human activity,I set administrator="adm_a",subject="subject_a".In the second activity,I set administrator="adm_b",subject="subject_b".But atually the process' adm and subject always took vaules assigned in the first human activity.It seems that the process' adm and subject can only be assigned values once.
Symptom 2:
Besides that,another bug is that I must initialise DOs used in expression and variables at the same time.When I assigned a constant to DO used in a variable of process's subject in the start event and assigned values to DO used in expression of process' administrator in the first human activity, the process couldn't be start,an error showing "SourceDO must be populated..." in the log. However, when I assigned values to DOs used by administrator and subject in the same place--the start event or the first human activity,the error didn't show again and the process started successfully.

Answer 1

Did you the expression for setting the administrator as follows?
Example : getPrincipalByUniqueName("ID","user")
You can have dynamic texts for each task.
Goto UserTexts tab and create a variable and you can use the same variable under parameterized texts section
2. If you are using the DOs in the expressions to compute values then you should initialize the values
Anil
Edited by: Anilkumar Vippagunta on Nov 27, 2010 11:44 PM