There are two errors on the K5-II/K5-IIs Firmware 1.05 page, in the text and in the file names.
Latest K-5II/K-5IIs Firmware Update : Software Downloads | RICOH IMAGING
First they say:
PENTAX Firmware Update Software for K-5II/K-5IIs
Registered name
k5_2_104.exe (For Windows 10,133 Kbytes) , k5_2_104.zip (For Windows/Mac 10,062 Kbytes)
k5_2s104.exe (For Windows 10,133 Kbytes) , k5_2s104.zip (For Windows/Mac 10,062 Kbytes)
Which is all wrong.
Then:
Download the updated firmware file.
[K-5II]
- For Windows : k5_2_105.exe 10,133 Kbytes, LHA type, self-extracting files
- For Windows/Macintosh : k5_2_105.zip 10,062 Kbytes, zip type
[K-5IIs]
- For Windows : k5_2s105.exe 10,133 Kbytes, LHA type, self-extracting files
- For Windows/Macintosh : k5_2s105.zip 10,062 Kbytes, zip type
And below the download buttons you get the following file names:
K5-II WIN: k5_2_104.exe (instead of k5_2_105.exe)
K5-II Mac: k5_2_105.zip
K5-IIs WIN: k5_2s_104.exe (instead of k5_2s_105.exe)
K5-IIs Mac: k5_2s105.zip
Even so the k5_2s105.zip is inconsistent with the k5_2_105.zip filename (should be k5_2s_105.zip).
And they still haven't corrected this mess after 2 days. Amazing!