Ok. It is a vista home premium installation, and is completely up to date. The load finds all the references fine, though does warn that they were built under 2.12.2 (I have 2.12.1 right now). There is a message specific to RCurl which is "Loading required package RCurl" so that doesn't seem to be an issue. All the references are present in R/library/. Functionally, everything seems to run clean. I could install the most up to date build of R but my connection here is slow and 45M is a lot unless that is for sure the problem. Since I'm not the only one with problems, and the RCurl certificate messages helfile dates from 2006 - I don't believe this to be an OS issue anyway. The message I am getting is identical to that mentioned in the original posting.
Edit 1: If I enter the line 'getURLContent("
https://api.betfair.com/global/v3/BFGlobalService",ssl.verifypeer = FALSE)' the return is 'Error: Not Found'. If I use some other URL (such as www.betfair.com), I get a whole bunch of html returned beginning "<!doctype html><html><head><meta http-equiv=\"content-type\" content=\"text/html; charset=ISO-8859-1\">, but it doesn't help login access.
It may or may not be relevant that my default browser is Firefox.
Edit 2: Reading up on RCurl / curl, it seems this isn't a new issue. There are a number of historical issues relating to aged certificate packs being shipped with libcurl. As far as I can make out, this was fixed; so I updated (now on 2.14.0), and checked with IE9 as default, FFx as default, and with the Internet2.dll enabled. I still get the same 'certificate verify fails' message, and am about at the limit of things I can think to try. Betfair seems to understand my Mozilla certificates, so why can't curl resolve this? So far, getting nowhere fast. Any suggestions as to what else I can try?