Hi Kay,
Sorry for the inconvenience caused.I was not able to reproduce the issue(slow dragprovider).
There are some problems in painting when we drag controls.This is a known issue and we are currently working on it.The reason for this painting issue is the existence of any background process which paints any other controls very frequently
I have attached a sample.Please modify that to bring the issue(slow dragprovider) and send to me.It will be great help in resolving this issue
Thanks for using Syncfusion products.
Regards,
Joy
sample30.zip