Good catch! One question though, I'd hate to set useDingbats = FALSE and then have other users object on the grounds that they wanted the dingbats variation of small circles. Do you have any insight into whether most users care about this?
If there is some disagreement about what the optimal value is by class or user or problem, then we could introduce an option in the Print to PDF dialog. Short of this, I noticed there is a
pdf.options function which you could call (perhaps in .Rprofile) to set the global default for useDingbats to FALSE in your installation.
Thanks again for your input. Any additional insight you have much appreciated.