can you telnet into your controller?
if so, telnet in, enter your userid and pw. Then enter the following command:
dir logs
that should give you a DOS listing of all your log files and their sizes. their names will be yymmdd.odat and pdat (outlet and probe). the pdat should be roughly the same size since they run for 24 hours at a time (the outlet logs will vary based on how frequently outlets turn on/off but probes get read on a consistent interval). do you notice big variances in log sizes, are there days that are missing? if you can, post a screen shot.