In b.69 (64-bit; also in .58), I experimented with a centralized TNSNAMES.ORA file on a network drive. That worked great, but I needed extra DBA connections that I don't want to expose to the general populous, so I unset the TNS_ADMIN variable from Winders 7 64-bit Pro. Toad didn't recognize it as being unset, which I discovered was a limitation of the launcher I used (Object Dock) having a local copy of env vars at the time of its launch. No biggie, I'll just launch Toad the old-fashioned way, via menu shortcut.
Toad no longer sees the TNS_ADMIN env variable, but it can't connect to the DB using the local copy of TNSNAMES.ORA. When I try to connect, I get a popup of: "ORA-12154: TNS:could not resolve the connect identifier specified" In that popup, I tried the Copy button, but it didn't put anything on the clipboard. The tnsping button pops up another window with a successful connection to my DB. Likewise the server ping comes back correctly (and fast). Clicking on the TNS button brings up the correct local TNSNAMES.ORA in the correct ORACLE_HOME with the DB entry intact. The SQL button brings up the SQLNET.ORA file, which should also be correct (it attempts to put many items not currently existing in my SQLNET.ORA). The rest of the window is in the attached expurgated screenshot.
My PATH is a bit hosed, possibly. It contains the path to the expected ORACLE_HOME's bin directory, but is preceded by another, which is in turn preceded by an Instant Client path. However, this hasn't been an issue in the past.
Also, the "Additional home properties" ellipsis button in the connection dialog shows two correctly configured ORACLE_HOMEs, with the "Advice" button greyed out.
Phew! Thoughts anyone?