Yeh we have had the odd issue, in most domestic installs we fit the quad linear with selectable pet immune as standard now,but on a few occasions we have had to revise the PIR's adjustments and position.
Had one where the cat was mental it ran up Walls and curtains,they also said the cat used to run up the wall and attack the pir,they even said they saw their beloved cat clinging onto it with both paws.
We got round that one by fitting a ceiling flush mount,technology has moved so fast over the years, I can remember back in the old days when you could fit pet lenses to most Passover, what a load of shite they were.I mean they filtered out nearly everything apart from an elephant, you could also sneak under them if you knew the pir,s location.
The modern range tend to need a bit more planning but still are not that stable,especially if the home has a mental moggy :-D
e manno
July 2012