Hi XRok,
This is a known issue in earlier versions and we have fixed the compatibility issues of our controls in our 4.1 and above releases. These releases have complete compatibility support of Visual Studio 2005 RTM. You should upgrade to v4.1 or latest from the download link below for this fix.
http://www.syncfusion.com/Downloads/product.aspx
If you still see the problem after upgrading, send us the sample which reproduces this issue. Please let me know if you have any questions. Thanks for using Syncfusion products.
Best Regards,
Seetha