Since updating to version 0.38.0 and 0.38.3 the speed limiter won't work anymore.
I have it set in the setup/options to 80% and have set my limit to 1200 kbs.
It works for about 30 seconds, then automatically resets back to no limit after this.
If I manually press 70%, 80%, 90% in the bottom left hand corner, it again works for about 30 seconds, then just automatically resets back to "No limit"
If you require any further information or want me to test it, please let me know.