What card and what OS are you using?
The base format used by media is a *standard*!!
If the formatting was different between the computer and camera you could not read/write across devices.
In general it is myth propagated by people who should know better (i.e. name rhymes with Scott Melby) with such phrases as "I've never had a problem, but just in case I always format in camera"
That type of statement doesn't even make any logical sense!
Regarding pentax:
It does not matter if you format in camera or on the computer!
Regarding other bands:
Some camera brands include additional database files while formatting. The actual format is standard, but the camera may not operate without these additional files that are created only during in-camera formatting.
It is unlikely without some effort but be sure you do not, for instance, format a high capacity card in old FAT format. This could turn your 32GB card into a 2GB card. But the card should still be functional. But as far as the Pentax models, it does not mater if the card is formatted on your computer.
The card may be faulty or the OS may not be capable of understanding newer high capacity cards. (the latter being less likely)
As a start, I would use something like the SD Card formatter referenced above, or find 'f3write' (
F3 by Digirati) which can test the card... and in that process potentially help knock out some bad spots.
---------- Post added 09-24-15 at 04:23 PM ----------
As an off-the-wall question... this isn't a Eye-Fi SD card is it?
Generally they won't even show up if the card reader isn't fully capable of supplying the necessary power to the card. But I could believe all sorts of problem being possible.
Many SD card reader manufacturers cheat on supplied power capacity and can not support the power requirements of the EyeFi Card (or so they say).
If it is an EyeFi card, be sure to use their included card reader.