I am not sure what the root cause ,but I got error when click on pdf document "There was an error opening this document. The filename, directory name, or volume label syntax is incorrect." when I install adobe reader current XI. What it look like is the Adobe try to open pdf on client mode not browser mode that causing the issue. Here is my work around
1) Create a copy of Item_PDF.html template say Item_PDF_Custom.html.
2) modifiy from ctx.CurrentItem.csr_OpenControl = "PdfFile.OpenDocuments";
to
ctx.CurrentItem.csr_OpenApp = "word";
3) Go to site -> Search ->result type
4) create a copy of PDF and point to new item create in step 1 and give it a new name.
