[Zope] anyone seen browsers map '_' to '+AF8-' ?

[Anthony Baxter]

We're seeing a really strange occasional error crop up in our
web logs - periodic requests for an image with an _ in the name
(e.g. hdr_left) get mutilated to hdr+AF8-left. Out of the last
400,000 requests, there's been about 110 of these errors. There
appears to be nothing much in common in the requests, except that
the browser is always a variant of IE 5.0 (not 5.01, 5.5, or 4.0,
or anything else). IE 5.0 only makes up 35% of our hits, so it's
unlikely to be just random chance.

Ones we've seen with it:
Mozilla/4.0 (compatible; MSIE 5.0; Windows 95)
Mozilla/4.0 (compatible; MSIE 5.0; Windows 95; DigExt; OZEMR1999V01)
Mozilla/4.0 (compatible; MSIE 5.0; Windows 95; ZDNetSL; DigExt)
Mozilla/4.0 (compatible; MSIE 5.0; Windows 98; DigExt)
Mozilla/4.0 (compatible; MSIE 5.0; Windows 98; DigExt; Chariot)
Mozilla/4.0 (compatible; MSIE 5.0; Windows 98; DigExt; TUCOWS)
Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)

Has anyone seen anything similar? I've searched the web, microsoft.com (ha), 
all to no avail. It's not a very common bug, but it's a significant
proportion of the total errors on the site, so it'd be nice to nail it.

ta,

Anthony

--
Anthony Baxter     <anthony@interlink.com.au>
It's never too late to have a happy childhood.