As I mentioned to Daniel and in my previous post, I will setup a sample and see if and why this could be happening.  This is actually not strange behavior for any container control.  When an internal object re-renders, it can for an OnPaintBackground of the parent control.  But in any case, I will set this up next week and let you know what I find.

These tips are definitively helpful, however I have also found that switching off Glass Effect on the form helps.

Regarding original question in this thread - any ideas why groupbox is being redrawn more than once or twice?

Sorry, I missed this post.

I actually spoke with Daniel the other day on the phone.  I gave him some tips to improve performance.  A couple of the tips were:

1. Set the FillBody to False
2. Set the TransparentBackground to False

Also, since our conversation, I have it on my list to see if there is anything behaving out of the norm and if there is an issue.  But that is the first place to look at.

I have been looking into some performance issues and I have come across potential issue (Winforms feature) with ThemedGroupBox.

It seems to me that ThemedGroupBox is redrawn again and again for every textbox on the form. Is this expected behavior or am I missing something? 

My test form has 24 text boxes and I traced OnStrataPaint execution 27 times.  Similarly  I am having our own component which is replacing groupbox with some effects and I am seeing similar execution counts.  

Thanks for your help.