This one is hard because you mention outside your job description... and I have been there before too.
Your manager usually wants you to stay in his/your box of work.
He doesn't want to lend you out for work outside your description - because you are the asset he has paid for, trained, hired, etc.
If you start looking and asking for work outside of his realm, you risk being labeled as no longer interested in your group. Just be careful of that.
Now if the other work is still under his direction, that may be different - so look into that.
The other thing to be aware of is, can the work out side of the description be considered learning for a future value to your manager. This is more along the lines of I would really like to be trained in X can I be mentored by Y. But, I am not getting that vibration from your question.
I would sit down with him and ask what type of things can I work on right now, so when things start to pick up - they will run more efficient and smooth. Or, is there work someone else is doing within the job description that you can help them, etc.
I am not saying it is "bad" to look for work outside of your description but be careful not to disconnect yourself...