I am turning on MOSS output cache. (This is working fine on some other
sites).

When I check the option

Page layouts can use a different page output cache profile

Click Okay.. the navigation menu disappears, only top site tab remains
in navigation and a new tab called Error appears.
When I hover over the error tab.. it displays
title="An error occured while rendering navigation for requested URL:
/. Exception message: Value does not fall within the expected range.
Stack trace: at
Microsoft.SharePoint.Library.SPRequestInternalClass.GetMetadataForUrl(String
bstrUrl, Int32 METADATAFLAGS, Guid& pgListId, Int32& plItemId,
Int32& plType, Object& pvarFileOrFolder)
at Microsoft.SharePoint.Library.SPRequest.GetMetadataForUrl(String
bstrUrl, Int32 METADATAFLAGS, Guid& pgListId, Int32& plItemId,
Int32& plType, Object& pvarFileOrFolder)
at Microsoft.SharePoint.SPWeb.GetMetadataForUrl(String relUrl,
Int32 mondoProcHint, Guid& listId, Int32& itemId, Int32&
typeOfObject, Object& fileOrFolder)
at Microsoft.SharePoint.SPWeb.GetFileOrFolderObject(String strUrl)
at Microsoft.SharePoint.Publishing.CommonUtilities.GetFileFromUrl(String
url, SPWeb web)
at Microsoft.SharePoint.Publishing.PublishingPage.get_Layout()
at
Microsoft.SharePoint.Publishing.PublishingPage.GetEffectivePageCacheProfileId(Bo\
olean
anonUserProfile)
at
Microsoft.SharePoint.Publishing.PublishingPage.GetEffectiveAnonymousPageCachePro\
fileId()
at Microsoft.SharePoint.Publishing.CachedPage..ctor(PublishingPage
page, SPListItem altItem, String id, String parentId, String title,
String url, String description, CachedObjectFactory factory,
List`1& fieldInfo)
at
Microsoft.SharePoint.Publishing.CachedPage.CreateCachedPage(PublishingPage
page, SPListItem altItem, CachedObjectFactory factory, List`1&
fieldInfo)
at
Microsoft.SharePoint.Publishing.CachedObjectFactory.CreateObject(PublishingPage
adminPage, PublishingPage readerPage, List`1& fieldInfo)
at Microsoft.SharePoint.Publishing.CachedArea.GetChildPageIds()
at
Microsoft.SharePoint.Publishing.Navigation.PortalWebSiteMapNode.PopulateNavigati\
onChildren(NodeTypes
includedTypes)
at
Microsoft.SharePoint.Publishing.Navigation.PortalSiteMapNode.GetNavigationChildr\
en(NodeTypes
includedTypes, NodeTypes includedHiddenTypes, OrderingMethod ordering,
AutomaticSortingMethod method, Boolean ascending, Int32 lcid)
at
Microsoft.SharePoint.Publishing.Navigation.PortalSiteMapNode.GetNavigationChildr\
en(NodeTypes
includedHiddenTypes)
at
Microsoft.SharePoint.Publishing.Navigation.PortalSiteMapProvider.GetChildNodes(P\
ortalSiteMapNode
node, NodeTypes includedHiddenTypes)"
id="zz1_TopNavigationMenun1"><table class="ms-topnav
zz1_TopNavigationMenu_4 ms-topnavselected zz1_TopNavigationMenu_10"
cellpadding="0" cellspacing="0" border="0" width="100%">