Posted by Jon on January 24, 19100 at 16:55:16 from 199.158.80.12:
In Reply to: Tarboard update problems posted by Dave W on January 24, 2000 at 08:18:49:
The problem, as Ian and I were able to determine, is that the WWW SERVER used by es-parto.lancs.ac.uk is not Y2K compliant. The differences in behavior between Netscape and Internet Explorer are because of the different ways they verify cached content. I'm experiencing the problem with IE running the latest updates to Windows 98 and Windows NT 4.0.
Essentially, the server is returning an invalid "Date Modified" value (ex. 01/01/:0) which IE interprets as older than the current cached copy. IE then does not request the full page since it has a "newer" version in cache. When IE brings in a new page with the invalid date, it uses the current system date for the "Modified" date. Netscape apparently sees the invalid date and doesn't cache the page because of it.
Standard browser behavior in the case of a malformed "Date Modified" value is "undefined", which means it's up to the vendor to decide how to handle it. In this case, Microsoft and Netscape chose different approaches. Which is better? For a changing page like the TARBoard, Netscape's works better. If the page in question was a similarly-sized static page, Microsoft's would result in faster response, since Netscape would have to download the entire file every time it was visited. Microsoft's is also better suited to their "Off-Line" capabilities.