Image_tag bad src generation

Hi everybody, I’m fighting with iis and fastcgi for deployment on a
windows 2003 server!

I’m running rails 2.1 and everithing untill now seems to work fine
except the src attribute of image tags gereated by image_tag helper

when the “?1234565” query string is appended to the image url also a “.”
is appended just before the “?” and after the image file extension.

For example

image_tag(“header.png”)

generates

Header

This happens only on iis, not if I run webrick on the server…

Does anybody know how can I fix it??

Thanks!