OnPageShow and OnPageHide are new HTML5 event attributes, and as such will only enjoy limited browser support (at the time of writing)
Its more likely that later versions of incumbent browsers will support it. Firefox certainly will, as will Safari according to this article.
I couldn't find anything that stated it definitively, but I would say that its likely that these events aren't supported in the version of IE that you are using. Can you maybe post this information for clarification.
Hope this helps