Threshhold line is misleading on plotters in Memory Tab.(Please see the attachement)

Plotters include all the pool plotters except for the Eden Space and Survivor Space.

Steps to Reporduce:
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1. After running jconsole, go to MBeans Tab, expand the "MomoryPool" in the tree on the let-hand side.
2. Click and on the "Tenured Gen" and the set the "UsageThreshhold" to some value.
3. After sometime change this value to some other value.
4. Now go to Memory Tab and observe "Tenured Gen" chart.
5. you will see a diagonal line between the previous and the new Threshholds, which is misleading.

Follow the steps to see the behaviour with ohter pools.


###@###.### 2005-03-28 19:28:01 GMT
###@###.### 2005-03-28 19:33:57 GMT