title: ggplot2 error after upgrade to version 2.0
body: <p>I have some code that no longer works since upgrading to the latest ggplot2 version. It's been out since early December and I'm wondering if anyone else has the same problem.</p>
  
  <p>The following code used to work perfectly:</p>
  
  <pre><code>gLM1 &lt;- ggplot(data = raw.data, aes(x = predict.lm1, y = (Sales_C-predict.lm1))) +
  geom_point(alpha = I(0.75), colour = myPal[1]) +
  geom_smooth(span = 0.75, degree = 1, size = 1.25, se = FALSE, colour = myPal[5]) +
  labs(list(title = "Fitted vs Residuals", x = "Fitted Values", y = "Residuals")) +
  theme_bw() + myGgTheme
  gLM1
  </code></pre>
  
  <p>Now is suddenly returns this:</p>
  
  <blockquote>
    <p>Error: Unknown parameters: degree</p>
  </blockquote>
  
  <p>It works again if I remove the degree parameter from the geom_smooth.
  Similarly, this code used to run and now fails:</p>
  
  <pre><code>gclus &lt;- ggplot(data = raw.data, aes(x = oOrollingSD, y = OnTarget, colour = clusterGroup, size = Quota)) +
  xlim(4.2, 11.8) +
  geom_point(alpha = I(0.75)) +
  geom_vline(x = 7.8, linetype = "dashed", colour = myPal[3]) +
  scale_colour_manual(values = myPalContrasts[c(7,3,4)]) +
  theme_bw() + myGgThemeSilentX
  gclus
  </code></pre>
  
  <p>The error is</p>
  
  <blockquote>
    <p>Error: Unknown parameters: x</p>
  </blockquote>
  
  <p>It works again if I remove the <code>geom_vline</code> (I can't simply remove the x parameter here as that is what makes the vline position!</p>
  
  <p>All this code was working correctly until yesterday. I ran it literally dozens of times in the last few weeks preparing a report. I read about the latest release of ggplot2 and updated it yesterday and these errors have appeared.</p>
  
  <p>My ggplot2 version is 2.0, all my other session info is below. I don't recall what ggplot2 version I was on before:</p>
  
  <pre><code>R version 3.2.2 (2015-08-14)
  Platform: x86_64-w64-mingw32/x64 (64-bit)
  Running under: Windows 8 x64 (build 9200)
  
  locale:
  [1] LC_COLLATE=English_Singapore.1252 
  [2] LC_CTYPE=English_Singapore.1252   
  [3] LC_MONETARY=English_Singapore.1252
  [4] LC_NUMERIC=C                      
  [5] LC_TIME=English_Singapore.1252    
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets 
  [6] methods   base     
  
  other attached packages:
  [1] dplyr_0.4.3     readr_0.1.1     stringr_1.0.0  
  [4] knitr_1.11      ggplot2_2.0.0   lattice_0.20-33
  
  loaded via a namespace (and not attached):
   [1] Rcpp_0.12.1      digest_0.6.8     assertthat_0.1  
   [4] R6_2.1.1         grid_3.2.2       plyr_1.8.3      
   [7] gtable_0.1.2     DBI_0.3.1        magrittr_1.5    
  [10] scales_0.3.0     highr_0.5.1      stringi_0.5-5   
  [13] lazyeval_0.1.10  curl_0.9.3       rmarkdown_0.8.1 
  [16] labeling_0.3     tools_3.2.2      munsell_0.4.2   
  [19] parallel_3.2.2   colorspace_1.2-6 htmltools_0.2.6 
  </code></pre>