Wrong report on used/available memory on external SD card

On web.airdroid.com my Samsung Galaxy S3 GT-I9300 running Android 4.1.2 with an external 32 GB micro SD is reported to have 11.25 GByte for both the internal memory and the micro SD card. Also exactly the same value of data used is reported for both the internal memory and the external micro SD card.
This info is however wrong.

The same problem with Samsung Galaxy Note II (Android 4.1.2) - 16GB (10.36GB) internal memory and 32GB (29.87GB) external microSD. But AirDroid shows 10.46GB internal and 10.36GB external. The "color indication" is totally wrong. And I also got some problems with links to folders in my external microSD card.

I have the same problem with my Galaxy S4

Same issue with Verizon Samsung Note 2.

Galaxy S4, came issue. Showing the same capacity and used space for both internal and external SD cards. Could this have something to do with how Android renamed the external SD card directory in 4.2? My external SD card is 64GB (S4 is 32GB model).

Same issue on LG Optimus G E970 (AT&T variant). SD card is reading same as internal.

Same issue with Sony xperia Z

Same issue on Galaxy Ace II.
As a quick, temporary workaround could we have an option which stop AirDroid checking the amount of space before uploading?

I have plenty of space on my external SD card but can't upload any music files because of the "Not Enough Space" error message.

Thanks in advance,
Antony

Also have this issue with Sony Xperia Z C6603