Wow! thanks for this beautiful plugin.
I'm running under php 5.3.3. - wordpress 3.5.
On line 111 in drag-to-feature.php you have mb_strtoupper().
This made the options page at appearance->DD options DIE in AGONY!
Also it killed the menu "fold outs". (the bloody savage!)
I changed it to strtouppper() and - IT'S ALIVE!!!
However I'm having some issues with displaying custom post_types in the options page so....
on line 86 where your get_post_types function is I force fed it ...
get_post_types( '','names') instead.
However I'm sure it could use a little filtering.
I'll keep an eye out for updates on that.
All good now.
I'm Sorry your beautiful plugin is sick.(on my server) I hope it gets better soon.
And Thanks for your great work!
P.S. I'm trying to make this work in a template or widget. I'll let you know if I have any luck.