We got a big problem with life cycle designer 8.
The processor become used at 100% level when we activate the xml source tab to check some values in our document.
It takes minutes to show the source and it is not possible to edit it easily. It takes a few seconds (5-10) for each manipulation (page down, page up, line down, line up, etc).
When editing something it is most of times not possible to come back to the design view, Designer continue consuming processor but didn't come back even after 10-15 minutes ... we have to stop the task and try again, try again and try again ..