this still seems to work for plesk 11.5:
Luckily the fix is pretty simple, but it's a shame it has to be done at all. To fix a domain that is "stuck" in the suspended state, run this from the command line on the server that is experiencing the problem:
/usr/local/psa/bin/domain -u example.com -status enabled
... replacing "example.com" with the name of your stuck domain (or sub-domain) and "/usr/local/psa" with the path to your Plesk installation (this should already be correct for most people).
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