You know, after searching info about jqDNR.js, I’ve met several issues with opacity problem during d-n-d. Though those issues were not like mine, I’ve removed all calls to E.css(‘opacity:… in the jqDNR.
And it helps!
I can’t explain this, but if opacity was changed during resize or dnd there are problems during form redraw.

Though it slightly concern your grid, I hope, this can help to smb else.