The Log is a bit confusing. It looks like, the adapter begin to scan an other mux, but the last scan is not completed.
Did you mean with "fresh installation" a delete configuration?
I don't know where the bug is. May be not en50494, but i am not sure.
2014-09-03 14:08:39.039 [ DEBUG]:mpegts:
12480V in astra - close PID 0BBB (3003)
2014-09-03 14:08:39.198 [ INFO]:mpegts: 12031.5H in astra - tuning on Conexant CX24116/CX24118 : DVB-S #0
2014-09-03 14:08:40.135 [ DEBUG]:en50494: lnb=0 id=0 freq=1210 pin=256 v/h=1 l/u=1 f=1431500, data=0x0D36
2014-09-03 14:08:40.595 [ DEBUG]:linuxdvb: Conexant CX24116/CX24118 : DVB-S #0 - starting 12031.5H in astra
2014-09-03 14:08:40.602 [ DEBUG]:mpegts:
12031.5H in astra - started
2014-09-03 14:08:40.619 [ INFO]:subscription: 'scan' subscribing to mux, weight: 4, adapter: 'Conexant CX24116/CX24118 : DVB-S #0', network: 'astra', mux: '12031.5H', hostname: '<N/A>', username: '<N/A>', client: '<N/A>'
2014-09-03 14:08:40.620 [ DEBUG]:mpegts: 12460.5H in astra - no free tuner available
2014-09-03 14:08:40.621 [ DEBUG]:mpegts:
12480V in astra - no free tuner available