Report builder hiding in Task bar

https://community.oracle.com/message/932489#932489

Hello,
Can you check if your problem is not the one described here below :

PROBLEM DESCRIPTION
-------------------
When starting Reports Builder or Forms Builder on Windows, the icon appears
in the taskbar but the Forms or Reports Window is not visible.
If you right click on the icon in the taskbar and choose Maximize, the 
window appears.
As soon as you click on the Restore window button, the window is not 
visible on the screen anymore. 

SOLUTION
--------
Modify the file CAUPREFS.ORA or CAGPREFS.ORA and change the line 
containing window position information:

For reports:

Reports.root_x = 0
Reports.root_y = 0

for Forms

Forms.root_x = 0
Forms.root_y = 0

EXPLANATION
-----------
Sometimes, the values stored in this file are erroneous (too big). In this
case the window position is "out of the screen" and it is not visible.

Regards