[BioC] biomaRt error: useMart fails

[michael watson (IAH-C)]

Hi

Sorry if this has been covered before, I did search the archives but I
didn't find a solution.

I'm using R 2.3.1 on windows and bioMart 1.6.0 (the BioC 1.8 release
version)

> library(biomaRt)
Loading required package: XML
Loading required package: RCurl
Warning message:
use of NULL environment is deprecated 

> mart <- useMart("ensembl")
Error in curlPerform(curl = curl, .opts = opts) : 
        couldn't connect to host

> mart <- useMart("ensembl", dataset = "hsapiens_gene_ensembl")
Error in curlPerform(curl = curl, .opts = opts) : 
        couldn't connect to host

I know some people have been getting this "couldn't connect to host"
error before, but I didn't find a solution.

Many thanks

Mick