When dragging a code template containing the syntax ||object_name|| it appears to drop a | and copies it as |object_name||
WORKAROUND
Download the following file if you have 7.0 Professional Edition installed only
http://toadsoft.com/sqlnavigator/GA/7_0_Patch/3027/sqlnavigator.zip
Rename the sqlnavigator.exe in SQLNavigator v7.0 installation folder before copy the new .exe which can be extracted from zip file.
The default installation folder of SQL Navigator v7.0 would be in C:\Program Files\Quest Software\SQL Navigator for Oracle7.0 or C:\Program Files (x86)\Quest Software\SQL Navigator for Oracle7.0 for Windows7.
STATUS
Waiting for a fix in a future release of SQL Navigator for Oracle