We have a site we are looking to deploy that is on our development server. It seems to hang and error out frequently. Can you tell me some remdies to try based on the stack trace below?

Stack Trace:

[IndexOutOfRangeException: Index was outside the bounds of the array.]
System.Array.InternalGetReference(Void* elemRef, Int32 rank, Int32* pIndices) +0
System.Array.SetValue(Object value, Int32 index) +59
System.Collections.Hashtable.CopyKeys(Array array, Int32 arrayIndex) +85
System.Collections.KeyCollection.CopyTo(Array array, Int32 arrayIndex) +78
CMS.CMSHelper.SessionManager.GetUsersWhereCondition(String location, String siteName, Boolean includeHidden, Boolean includeKicked) +1090
CMS.CMSHelper.SessionManager.GetOnlineUsers(String where, String orderBy, Int32 topN, String columns, String location, String siteName, Boolean includeHidden, Boolean includeKicked) +173
CMSWebParts_Membership_Users_OnlineUsers.SetupControl() +466
CMSWebParts_Membership_Users_OnlineUsers.OnPreRender(EventArgs e) +20
System.Web.UI.Control.PreRenderRecursiveInternal() +80
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842