Two weeks later and NO downtime  (Crossing fingers)!   I am either getting lucky or may have found a lead to at least try out. 

SIDE NOTE:  The hosting server I am experiencinig this on is going away in less than a month and I am moving to new 64bit blades.  I will report back if the issue shows up on the new server because I plan on leaving on "Application Pool Recycling" and standard settings but all 64bit (OS,IIS, SQL)

Hello,

It happened to my 4.8.2 installation 2 times at a distance of some days each other. The problems appeared on the morning.

I just want to know if some work is in progress to fix those errors. Thank you.

As you can see below the exceptions (4 in total in less than 4 seconds, i post only the last) appeared at 19hr, a time on which our server is not heavily used, but the problem (disappearing navigation menu and error if one try to navigate to a page) persists until the morning.

A detail: at 19.11 EventViewer reports that an application pool has request a recycling event (Event ID 107 - w3svc)

Thank for your  time, goodbye

Attachment, Exception:

18/09/2008 19.15.19   General Exception       AssemblyVersion: 04.08.02;

PortalID: -1; PortalN ... 
AssemblyVersion: 04.08.02
PortalID: -1
PortalName:
UserID: -1
UserName:
ActiveTabID: -1
ActiveTabName:
RawURL: /Default.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer:
UserAgent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider,

DotNetNuke.SqlDataProvider
ExceptionGUID: 1391915b-42f5-4ea5-afa8-76d94df8d243
InnerException: Index was outside the bounds of the array.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Collections.Generic.Dictionary`2.Insert
StackTrace:
Message: System.IndexOutOfRangeException: Index was outside the bounds of the
array. at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue
value, Boolean add) at DotNetNuke.Entities.Tabs.TabController.FillTabInfo(IDataReader dr, Boolean
CheckForOpenDataReader, Boolean CheckForLegacyFields) at
DotNetNuke.Entities.Tabs.TabController.FillTabInfoDictionary(IDataReader dr)
Source:

I get these errors too. I am on 4.08.02.

I would be interested in hearing from anyone that has had these errors and whether upgrading fixed them.

As a general observation, when there is a problem reported, it is not very helpful to be told "upgrade because there have been several changes". The community is well aware of the benefits of running the latest codebase. However unless someone gets to the root cause, who is to say the problem has been fixed in the latest version?

charlie.

www.agilesoftware.com.au