What are these /(null) 404s?

[pageoneresults]

Anyone else seeing a rise of 404s with /(null) being appended to valid URIs?

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)

They have become quite frequent over the past week or so. I'm going to guess that this is related to the beta release of IE8?

[Samizdata]

Sightings discussed at [webmasterworld.com...]

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