I have a weird problem with my SP2013 server and Word 2013. Whenever I try to open a word document from a Sharepoint library, MS Word 2013 on the client computer starts veeery slowly (the "Loading Word" splash screen hangs for more than 2 minutes). After loading the document however, everything works fine. When opening a document from the local drive, Word starts instantly.
I already tried unticking "automatic proxy setting" in Internet Explorer, setting the Web Client Service via registry but nothing has helped.
The strange thing is that all other office doc types (e.g. excel, ppt) are downloaded and opened really quickly. I tried using Office 2007 on an XP machine and Word loads the same file within a second.
The only specific of my environment is, that it is an intranet site with no internet access. It is probably the reason for Office 2013 logging MSOIDSVC errors when opening a doc/xls from Sharepoint. I also discovered some 401 auth errors using Fiddler but these do not seem to slow things down - the same sequence appears with excel files, which load quickly.
Many thanks in advance for any clue.