We have been getting an error on using SmartUI with a ESRI map based vb application. The error popup seems to show up randomly and the SmartUI works fine without the ESRI integration. We are using COM interop to call a .Net wrapper around ESRI which also uses COM. 

The popup says:

 Run-Time Error '0' and has the title Xceed SmartUI.

In order for us to investigate this issue further we would have to be able to reproduce it. If you ever find a pattern or a way to reproduce this, please let me know. We are not able to reproduce this issue on our end.

Keep in mind that we cannot guarantee compatibility of our control through .NET wrappers.