Purchase Requisition Screen Taking too long to open

Hello Guy's, 

Our client is currently experiencing challenge with Sage 300 Purchase Requisition Screen in one of their company database. When the client click on the Requisition Entry it take about 15 minutes for the Requisition screen to open on the Server and the screen is not opening in any of their Workstations for this particular database(company), but the Requisition Entry is working fine for other companies database on the same server.

Sage 300 Version: 6.1A

Product Update: 3

SQL Server: 2008

Window Server: 2005

You advise on how to resolve this error will be highly appreciated.