Setdatasource to Crystal Report

Question

Hello Everybody

i use a crystalReport in C# 2008 with SQL 2005

the problem is when i try to sned the Dataset to my crystalreport 

crystalreportName.SetDataSource(Mydataset.Tables["MyTables"]);
this line take 60 sec in some computer in first call only
but if i use this code after it run normally 
i have this problem in my computer but not in my laptop
i try hardly to know what is the difference  between them  but i cant find it
if some one have any idea about this problem  i ll apperciate any help
thanks