About reprobes resulting in spikes..
Actually, that's quite logic..
In most cases The Dude uses a certain interval for the probe, let's say every 15 seconds.
When you reprobe the device you're very likely to do so somewhere in between two polls.., the returned value seems to be stored somewhere and when the regular poll is there it's added to that one.
I've lots of AKCP SensorProbes here, monitoring temperature and relative humidity.
When I already have a returned value of 65% RH, then reprobe between 2 polls and the device returns 66% RH, the next poll is again 65%, then I'm very likely to run into a spike of 131% RH (or even 196% RH in worst case scenario's), which is obviously not likely to be for real or my device would be swimming..
Hope this helps (or better, it doesn't really help..