Fragment caching works only on production server?

[Jens]

Hello,

I've created a user control with fragment caching:
<%@ OutputCache Duration="43200" VaryByParam="none" %>
<% =now() %>

In my local environment (PC with Visual Webdeveloper 2005) the caching
of the control doesn't work because the displayed time is updated each
time I refresh the page.

When I upload the control to my production server (Win2003 with IIS)
the caching works correct.
Can anyone tell me what causes this problem?

regards,
Jens