Nope - no errors. Both reports run fine.
re: "Recently Written Media" I think the key word there is "recently". It seems to have a hard-coded maximum, even though the "Hours" range setting is available. Whether I run it without an entry in "Hours" or with a "30" in "hours" or with a "50" in "hours, it reports the same very recent data. And the PDF format just needs adjusting - the field mask for the column labelled "SET" is way too short. I said in the original post it caused the data in the column to overwrite Media Label, but it actually overwrites "Date and Time Modifed" - the column to the right of "Set".
Correction from my original post: The 2nd report that has a problem with ranges, in this case servers, is not the "Backup Resource Success Rate" but "Backup Set Details by Resource". Apologies.