Summary and Info:
Pacman attempts, but fails, to import keys it hasn't seen before when installing packages from official repositories. Importing them using pacman-key --recv-keys works fine.

Steps to Reproduce:
Followed instructions at http://allanmcrae.com/2011/12/pacman-package-signing-4-arch-linux/ to install, sign and trust master keys.


$ pacman -Suy
[snip]
Targets (2): gpgme-1.3.1-2 ttf-junicode-0.7.1-1

Total Download Size: 1.02 MiB
Total Installed Size: 3.39 MiB
Net Upgrade Size: -0.06 MiB

Proceed with installation? [Y/n]
:: Retrieving packages from core...
gpgme-1.3.1-2-x86_64 [progress...]
:: Retrieving packages from extra...
ttf-junicode-0.7.1-1-any [progress...]
(2/2) checking package integrity [progress...]
error: gpgme: key "1EB2638FF56C0C53" is unknown
:: Import PGP key F56C0C53, "Dave Reisner <d@falconindy.com>", created 2011-06-25? [Y/n]
error: key "Dave Reisner <d@falconindy.com>" could not be imported
error: ttf-junicode: key "F3E1D5C5D30DB0AD" is unknown
error: key "F3E1D5C5D30DB0AD" could not be looked up remotely
error: failed to commit transaction (invalid or corrupted package (PGP signature))
Errors occurred, no packages were upgraded.



$ pacman -Su
[snip]
Targets (2): gpgme-1.3.1-2 ttf-junicode-0.7.1-1

Total Installed Size: 3.39 MiB
Net Upgrade Size: -0.06 MiB

Proceed with installation? [Y/n]
(2/2) checking package integrity [progress...]
error: gpgme: key "1EB2638FF56C0C53" is unknown
:: Import PGP key F56C0C53, "Dave Reisner <d@falconindy.com>", created 2011-06-25? [Y/n]
error: ttf-junicode: key "F3E1D5C5D30DB0AD" is unknown
:: Import PGP key D30DB0AD, "Andrea Scarpino <bash.lnx@gmail.com>", created 2011-04-19? [Y/n]
error: key "Andrea Scarpino <bash.lnx@gmail.com>" could not be imported
(2/2) checking package integrity [progress...]
error: ttf-junicode: key "F3E1D5C5D30DB0AD" is unknown
error: key "F3E1D5C5D30DB0AD" could not be looked up remotely
error: failed to commit transaction (invalid or corrupted package (PGP signature))
Errors occurred, no packages were upgraded.

(note: it tries both keys this time, but only one the first time).

$ pacman-key --recv-keys F56C0C53
gpg: requesting key F56C0C53 from hkp server subkeys.pgp.net
gpg: key F56C0C53: "Dave Reisner <d@falconindy.com>" not changed
gpg: Total number processed: 1
gpg: unchanged: 1
==> Updating trust database...
gpg: no need for a trustdb check


$ pacman-key --recv-keys D30DB0AD
gpg: requesting key D30DB0AD from hkp server subkeys.pgp.net
gpg: key D30DB0AD: public key "Andrea Scarpino (Arch Linux) <andrea@archlinux.org>" imported
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 1 signed: 5 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 5 signed: 2 trust: 0-, 0q, 0n, 5m, 0f, 0u
gpg: depth: 2 valid: 2 signed: 0 trust: 2-, 0q, 0n, 0m, 0f, 0u
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
==> Updating trust database...
gpg: no need for a trustdb check


$ pacman -Su
[snip]
Targets (2): gpgme-1.3.1-2 ttf-junicode-0.7.1-1

Total Installed Size: 3.39 MiB
Net Upgrade Size: -0.06 MiB

Proceed with installation? [Y/n]
(2/2) checking package integrity [progress...]
(2/2) loading package files [progress...]
(2/2) checking for file conflicts [progress...]
(2/2) checking available disk space [progress...]
(1/2) upgrading gpgme [progress...]
(2/2) upgrading ttf-junicode [progress...]
Updating font cache... done.