A new version of RPostgreSQL just went out to CRAN and should propagate via the mirrors over the next few days.
This is a maintenance and bug fix release that addresses four of the seven issue at the Google Code page. Two more are really enhancement requests for which we encourage patches as we are unlikely to have to write them, and the last issue I have been unable to replicate.
This release has benefitted greatly from the generous help of Neil Tiffin who now looks after all things OS X and keeps a good eye on the Google Code site (where I had, ahem. overlooked the existence of these open issue tickets for a few months), Joe Conway who we can count on for hard-core PostgreSQL issues as well as Jeff Horner for general R, DBI and database smarts.