i did mean to say when program is uploaded by isp. very inconvenient for projects like multiwii where all calibration and user settings are lost. using correct fuse avoids this.
obviously data can be corrupted if power is removed or unstable while writing to ee but that has nothing to do with my comments. mostly its caused by slow rise/fall regardless of what mcu is doing.
ee corruption is generally rare in most arduino setups and relatively few even use that feature so not surprising some deny its a problem. op (and i) know different. for example uno discharges quickly because of small caps and high idle current. this is a case where big supply caps can work against you.
also worth mentioning that location zero is orders of magnitude more susceptible with adjacent address not far behind. thats why i always start at locations 1/3 the way up which are more resistant.
another thing to note is that if there is no ee write code anywhere in the program much less chance. so data loaded with a programmer is relatively secure.