Hello,
I have also the same problem in opening pdf files (the browser stop working when it start open and dowloading the file).
My site runs on Kentico 6 with hotfix 15 and the problem appears only on Internet Explorer browser, only with Adobe Reader X plugin and only hosted on Windows Azure. With Adobe reader 9 plugin the pdf file opens well on Azure , also on another hosting environment with Adobe Reader X it works well. I hope I make you an idea of my issue.
The files are uploaded with document attachments control and in my transformation I use this code line to show them on the page
<a target="_blank" href="<%# GetAbsoluteUrl(GetAttachmentUrl(Eval("AttachmentName"), Eval("NodeAliasPath")), EvalInteger("AttachmentSiteID")) %>">
<%# Eval("AttachmentTitle",true) %>
If you have an idea of how I can fix this I will be grateful. Maybe the team that develop for Azure environment knows the reason for this behavior.
Thanks,
Andrei