Encrption fails if gpgagent is running. The passphrase is never asked about, even if it was never entered. Encription fails with error "Bad Passphrase".
It does not help to enter the passphrase by calling any of the keyring tools directly. Same error: "Bad Passphrase" or "Incorrect Passphrase".
Encryption never takes a passphrase. Only signing (alone or combined with encryption) needs a passphrase. Please write exactly what you have done and when the error message pops up. Which operating system are you using?
Excuse me -- I meant signing.
OS: Ubuntu 14.04 (trusty) x86_64
⟫ gpg --version
gpg (GnuPG) 1.4.16
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Öff. Schlüssel: RSA, RSA-E, RSA-S, ELG-E, DSA
Verschlü.: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: MD5, SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Komprimierung: nicht komprimiert, ZIP, ZLIB, BZIP2
Please enable the debug log file, repeat the tests and search for "problem with gpg-agent" or "problem with pinentry".
Instructions for enabling the debug log are here: https://www.enigmail.net/support/bugs.php
No reply from reported; nothing to analyze or fix.