Interesting I tried at my side got the same results but it does work like this:

curl -I "http://backend.right.bike/images/models/Lapierre/Overvolt%20HT.png"
HTTP/1.1 200 OK
Server: nginx/1.9.1
Date: Fri, 12 Jun 2015 01:55:27 GMT
Content-Type: image/png
Content-Length: 318335
Last-Modified: Thu, 11 Jun 2015 10:09:54 GMT
Connection: keep-alive
ETag: "55795e72-4db7f"
Expires: Sat, 13 Jun 2015 01:55:27 GMT
Cache-Control: max-age=86400
Accept-Ranges: bytes



Melhores Cumprimentos // Best Regards
-----------------------------------------------
Miguel Clara
IT - Sys Admin & Developer


On Fri, Jun 12, 2015 at 2:52 AM, steve <steve@greengecko.co.nz> wrote:
> Just a quick addition... I've tried it from this office, which is IPv4, and
> from IPv6 enabled locations. This makes no difference.
>
>
>
> On 12/06/15 13:50, steve wrote:
>>
>> I'm tryiong to make some sense out of this and am left a bit cold! What
>> could cause this:
>>
>> ( I've left out any attempt at anonymising in case I hide something )
>>
>> From the docroot...
>>
>> $ ls -l images/models/Lapierre/Overvolt*
>> -rw-r--r-- 1 right-bike right-bike 342373 Jun 11 20:09
>> images/models/Lapierre/Overvolt FS.png
>> -rw-r--r-- 1 right-bike right-bike 318335 Jun 11 20:09
>> images/models/Lapierre/Overvolt HT.png
>>
>>
>> $ curl -I http://backend.right.bike/images/models/Lapierre/Overvolt\
>> FS.png
>> HTTP/1.1 200 OK
>> Server: nginx/1.9.1
>> Date: Fri, 12 Jun 2015 01:47:14 GMT
>> Content-Type: image/png
>> Last-Modified: Thu, 11 Jun 2015 10:09:52 GMT
>> ETag: "55795e70-53965"
>> Expires: Sat, 13 Jun 2015 01:47:14 GMT
>> Cache-Control: max-age=86400
>> Accept-Ranges: bytes
>> Content-Length: 342373
>> Connection: Keep-Alive
>>
>> $ curl -I http://backend.right.bike/images/models/Lapierre/Overvolt\
>> HT.png
>> HTTP/1.1 400 Bad Request
>> Server: nginx/1.9.1
>> Date: Fri, 12 Jun 2015 01:47:05 GMT
>> Content-Type: text/html
>> Content-Length: 172
>> Connection: close
>>
>> The second one shows no entry at all in the access log but I can't find
>> any reason why they're processed differently at all.
>>
>> Suggestions please!
>>
>
> --
> Steve Holdoway BSc(Hons) MIITP
> http://www.greengecko.co.nz
> Linkedin: http://www.linkedin.com/in/steveholdoway
> Skype: sholdowa
>
> _______________________________________________
> nginx mailing list
> nginx@nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx

_______________________________________________
nginx mailing list
nginx@nginx.org
http://mailman.nginx.org/mailman/listinfo/nginx