Possible bad string written to buffer

[153957]

"Interpreter: Event exception : time data '' does not match format '%Y-%m-%d %H:%M:%S'.

However, in the weather daq the string looked fine. After restarting the daq the problem went away.
This problem was encountered on/after July 12, 2012 and the daq was restarted on July 17, 2012:

No weather data at end of day: http://data.hisparc.nl/django/show/stations/501/2012/7/12/
No weather data: http://data.hisparc.nl/django/show/stations/501/2012/7/14/
No weather data at start of day: http://data.hisparc.nl/django/show/stations/501/2012/7/17/

[153957]

Weather Parameter String at time of error:
2012-07-16 09:07:49 22.166668E+0 18.944443E+0 57.000000E+0 .....