Fix invisible new grid row

[janschatz]

Fixes #294

This is rather a workaround than an actual fix of the root problem. But since the old grids are kind of deprecated, probably nobody will provide a better solution.

[janschatz]

Here is a fiddle demonstrating the fix.

[dylans]

Backported to version 1.8:

• 1.14: 943daf3
• 1.13: 86985d6
• 1.12: fd5606f
• 1.11: b9dac77
• 1.10: 88dc401
• 1.9: bac4680
• 1.8: 1309507