An updated firmware usually extends the media compatibility list inside the writer. You have a fair change of writing 8x at verbatim's when you upgrade to a better firmware revision.
Be sure to check the changelog of the firmware version.
If this fails , you could also try and find a hacked firmware , which usually accepts all media to the highest speed possible. See www.rpc1.org for more information. Be warned that flashing your writer will instantly void its warranty ..
Yes .. even when it's a firmware which is supplied by the official manufacturer/dealer/shop.