title: QuantMod getOptionChain "subscript out of bounds" error
body: <p>I am trying to use the function getOptionChain() from the QuantMod library to download option chains for VIX, SP500 and Eurostoxx 50 but the following doesn't work:</p>
  
  <pre><code>library(quantmod)
  VIX.OPT &lt;- getOptionChain("^VIX")
  </code></pre>
  
  <p>I'm getting this error: </p>
  
  <pre><code>Error in lapply(strsplit(opt, "&lt;tr&gt;"), function(.) gsub(",", "", gsub("N/A",  : 
    subscript out of bounds
  In addition: Warning message:
  In readLines(paste(paste("http://finance.yahoo.com/q/op?s", Symbols,  :
    incomplete final line found on 'http://finance.yahoo.com/q/op?s=^VIX+Options'
  </code></pre>
  
  <p>How can I fix this?</p>