GalaxyS (SGH-I897), running Android 4.0.4
Short problem description
I keep getting "Low on Space: Phone storage space is getting low" error in my notifications bar, but neither the SD card nor the phone appears to be close to full.
Please see below for screenshots showing the error, and also showing that both internal storage and SD card storage have plenty of space. Nonetheless, this error notification has been persistent for 2 weeks, and sometimes I even get an error when using gmail that says it can't sync because there isn't enough space.
This similar thread recommends the tool DiskUsage, which I installed, but the numbers reported by it match the numbers in the screenshots below.
Is there some other storage device besides internal storage or the SD card that I should be looking at? Maybe a subsection of the internal storage?
How can I fix this?
Internal Storage, 1.4G Free:
SD Card, 7.5G Free: