I believe you can fix this by getting the tool tip, see the getToolTips() method, in initDialog.  Then use the setMaxTipWidth() method.  Read the doc on the method.  Basically if you set the width properly, the tool tip should wrap the lines.

I've tried the setMaxTipWidth method and the method seems to execute OK but there is no visible effect on the label tips. The width is from what I can see expressed in pixels and I've tried some small values like 300 that really should show up, but no. Any ideas?