I've found a common bug in all Pale Moon NextGen browsers: By default, if "automatic cache management" is not used on a profile, the value for the cache is set to 1024MB as a user preference, ignoring the defaults set in the application's preferences.
This results in any new profile (after a fresh install, for example) to have a user-set value to 1GB. Pale Moon's design size is 200MB, to which some other parameters have been adjusted as well, and using a 1GB disk cache is not recommended for several reasons (most notably inefficient cache use, stale items and unnecessary cache management).
Please check and adjust your cache size:
- Go to Options -> category Advanced -> tab Network
- Check "Override automatic cache management" (this is the default setting)
- Adjust "Limit cache to" to 200MB
- Clear your cache ("Clear Now")
This bug will be fixed in Pale Moon 12.1, but since this is made as a user setting on each profile created, the setting will always prevail so an upgrade to that version will not fix your cache size automatically.
More technical details for the programmers among you: