Problem with design time rendering in VS2005


I have made a server control to display the average rating for content by
showing the number of stars. The problem i have is with the design time
display in vs 2005. It seems the problem with the design time rendering is
due to the calls to the databse helper class. Delete those lines and it
displasy fine in deign time. The code is below
Any ideas on how to make design time work?
Thanks Ashok

Dim dbutil As New DBHelper

Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)

dbutil.ProductID = _productid

Dim average As Single = dbutil.GetAverage

If average <> 0 Then

Select Case CInt(average * 4)

'load the right star image based on the rating

End Select

output.Write("Rating: ")

MyBase.Render(output)



.