Strange selection phenomenon

I got a problem of a font I made it by GlyphsApp. You can read in the image I attached. The left one is the old font I generated by FontForge, and the right one is a new edition that generated by Glyphs.

When I use the Font in Illustrator CS5, the old one have a normal selection highlight, but the NEW one have a abnormal highlight. I can not find out and fix this problem.But in and Textedit it appear normal.

Any suggestions!

You can compare the vertical metrics of the two OTFs with FontTableViewer (see the tools section of this website), then set the Vertical Metrics with custom parameters. This is explained in the Vertical Metrics tutorial.

And check if there is a very low node somewhere.

Yes! I find a little node down there. After clean it up, the problem gone. THANKS!