Thanks for the log. It appears that your LIPSLX print job is stuck with determining the toner status of the copier. After the print job is prepared and the backend canonoipnetzu has started the log shows the following
D [11/Aug/2015:07:37:45 +0900] [Job 5] ATTR: marker-levels=97,99,99,99,-1
D [11/Aug/2015:07:37:45 +0900] [Job 5] new_supply_state=0, change_state=0
This is repeated till the end of the log that you provided with no apparent attempt to send the spool file. In comparison, the error log for a print job to my ADV C5255 shows
D [07/Aug/2015:17:02:06 +1000] [Job 7] ATTR: marker-levels=80,86,57,79,-1
and then moves on to submitting the spool file
D [07/Aug/2015:17:02:06 +1000] [Job 7] Connecting to 10.10.52.55:9100
D [07/Aug/2015:17:02:06 +1000] [Job 7] PAGE: 1 1
I [07/Aug/2015:17:02:06 +1000] [Job 7] Connecting to printer.
D [07/Aug/2015:17:02:06 +1000] [Job 7] Set job-printer-state-message to "Connecting to printer.", current level=INFO
D [07/Aug/2015:17:02:06 +1000] [Job 7] STATE: -connecting-to-device
D [07/Aug/2015:17:02:06 +1000] cupsdSetBusyState: newbusy="Active clients, printing jobs, and dirty files", busy="Active clients and dirty files"
I [07/Aug/2015:17:02:06 +1000] [Job 7] Connected to printer.
D [07/Aug/2015:17:02:06 +1000] cupsdSetBusyState: newbusy="Active clients, printing jobs, and dirty files", busy="Active clients, printing jobs, and dirty files"
D [07/Aug/2015:17:02:06 +1000] [Job 7] Set job-printer-state-message to "Connected to printer.", current level=INFO
D [07/Aug/2015:17:02:06 +1000] [Job 7] Connected to 10.10.52.55:9100...
So in your log I don't see "Connecting to printer". But I don't think its being caused by the toner levels as the values indicate there is plenty of toner in each colour developer tank.
I know that your C5250 does not have the Postscript kit but I am curious to see if the cups error log shows the same log data as we are seeing for the LIPSLX driver. So could you create a new printer using the Canon Postscript driver and then send a print job and then obtain the cups error log for me to compare. I know the machine will show an error. But I also know that the print job will get to the copier and thus the error log should show it progressing past the toner marker level. Once you have the new log please post on Dropbox and I will compare the PS driver log to the LIPSLX driver log.