I suspect that you are loading the image from a file and the second form is
encountering a locked file.
See the GDI+ FAQ for details of a workaround for this problem.

Signature
--
Bob Powell [MVP]
Visual C#, System.Drawing
Ramuseco Limited .NET consulting
http://www.ramuseco.com
Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm
Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/faqmain.htm
All new articles provide code in C# and VB.NET.
Subscribe to the RSS feeds provided and never miss a new article.
>I have defined a picturebox control defined
> in the common class and i am loading the picturebox to a panel defined in
[quoted text clipped - 6 lines]
> visible
> property of a button in the toolstrip.