It seems if your primary disk is an SSD drive in my case a 1TB Samsung EVO 840, CCLEANER recognises all other drives also as SSD regardless
of been a second on the SATA controller or if it is an external USB drive.
Maybe something easy to fix, I do not think it is causing any issues other then the message that pops up if you want to secure erase a drive or claim space.
My system drive is a 60GB OCZ Vertex 3, CCleaner correctly detects it as an SSD, but also correctly detects my other 5 drives as HDDs and my raid 0 array as a single HDD as well. Windows 8.1u1 Pro x64, CC4.15
I forgot to attach one screenshot earlier that shows the other drives as SSD in this case I have attached two 2TB 2 1/2" Toshiba external USB 3 drives.
In fact it does not matter what brand or size attached it always shows SSD drives.
Anyhow as I said it does not seem to be causing any issues, well I have not noticed any.