It seems to be just arcpy.mapping that causes issues (for me anyway!). Using SubmitJob executation, I get a status of failed and this in the logging:
2012-07-01 13:24:34,378 INFO rid=116 'server' GPServer-exportmaptest - GET GPServer/Export Map Test/jobs/j73283e376de540ae8dfa830fd5475161?f=json&ts=1341105874377
2012-07-01 13:24:34,383 INFO rid=116 'worker-4540' STAServerObjectHost - Received Request.
2012-07-01 13:24:34,383 INFO rid=116 'worker-4540' Core - tasks/Export Map Test/jobs/j73283e376de540ae8dfa830fd5475161 (code=100001): REST request received. Request size is 0 characters.
2012-07-01 13:24:34,384 INFO rid=116 'worker-4540' Core - tasks/Export Map Test/jobs/j73283e376de540ae8dfa830fd5475161 (code=100004) (elapsed=0.000672904): REST request successfully processed. Response size is 951 characters.
2012-07-01 13:24:34,386 INFO rid=116 'server' GPServer-exportmaptest - Request handled.
2012-07-01 13:24:43,370 INFO rid= '' WebServer - Lost connection on port 50000
2012-07-01 13:24:43,384 INFO rid= '' WebServer - Lost connection on port 50000
2012-07-01 13:24:43,384 INFO rid= '' WebServer - Lost connection on port 50000
2012-07-01 13:24:44,386 INFO rid= '' WebServer - Lost connection on port 50000
2012-07-01 13:24:44,400 INFO rid= '' WebServer - Lost connection on port 50000
2012-07-01 13:24:44,409 INFO rid= '' WebServer - Lost connection on port 50000