AutoCad - Problemas al Abrir

Tengo un problema al abrir cualquier archivo con la secion de autocad ya abierta, al darle open o al icono del mismo, se queda pensando y no responde, pero si lo abro directamente desde el Explorador si los abre... Ya le revise la variable FILEDIA y esta bien y sucede tambien al darle NEW para crear....

Espero me puedan ayudar...

Hola me pasa exactamente lo mismo desde hace 3 días que sucede con el autocad 2015, por favor alguien nos puede ayudar?

Ya han instalado el Service Pack?

http://knowledge.autodesk.com/support/autocad/downloads/caas/downloads/content/autocad-2015-service-pack-1.html

Segun el sitio de Autodesk:

As a result of the detailed information that we received from customers who used the Customer Error Reporting Utility, several problems were identified and fixed. Updates have been made in the following commands and features:
DB Connect
Occasional crashes when using DB Connect feature on 64-bit machines with 4GB and more RAM.
Status Bar
Occasional crashes when opening drawing file when a bubble notification is still displayed.
New Tab
Occasional crashes when clicking New in the Quick Access Toolbar or the Start Drawing tile on the New Tab page.
Occasional crashes when clicking the New Tab Plus button after adding LayerFilterComboControl or Filter in the CUI dialog box.
Design Center
Occasional crashes when inserting a block from Design Center on the second time.
General
Occasional crashes when selecting the "Fully open the drawing file" option that displays when opening a drawing that was saved in the partial open state.
Occasional crashes when exiting AutoCAD.