I can't seem to replicate this error again, but yesterday I was receiving an ArgumentOutOfRangeException error when clicking the the RSS subscription link on www.stevebumbaugh.com.  After searching the web I found some information that implied there may have been time descrepencies between either my laptop (where I develop my site), the server (hosted somewhere at GoDaddy)  or BlogEngine.NET.  Adjusting the "Server time offset" on the BlogEngine.NET settings page fixed my issue (it was an hour off from our last time change in the fall).

I'll update this post with more information if I encounter this issue again or find more information on the topic, but for now I am unable to replicate the issue.

Update

This is still an issue that I am having with my site, http://www.stevebumbaugh.com/me/syndication.axd.  So, for now I am just fine tuning the server offset time, by setting to zero.  Unfortunately it's annoying to have to keep adjusting it back and forth in order to keep accurate local time on the site.

Here is the full stack trace:

[ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: utcDate]
   System.Web.HttpCachePolicy.UtcSetLastModified(DateTime utcDate) +3352787
   System.Web.HttpCachePolicy.SetLastModified(DateTime date) +47
   BlogEngine.Core.Utils.SetConditionalGetHeaders(DateTime date) in Utils.cs:129
   BlogEngine.Core.Web.HttpHandlers.SyndicationHandler.SetHeaderInformation(HttpContext context, List`1 items, SyndicationFormat format) in SyndicationHandler.cs:293
   BlogEngine.Core.Web.HttpHandlers.SyndicationHandler.ProcessRequest(HttpContext context) in SyndicationHandler.cs:65
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +358
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64