Error when using lubridate

gistfile1.r

# The Error
> mdy_hms(my_dates)
Error in data.frame(c("14", "19", "01"), c("14", "20"), check.names = TRUE,  : 
  arguments imply differing number of rows: 3, 2

# The Cause
> str_split(dates, fixed(sep[1]))
[[1]]
[1] "14" "19" "01"

[[2]]
[1] "14" "20"

# The Culprit - The following code is in the hms() call, which is called in mdy_hms().
> as.data.frame(str_split(dates, fixed(sep[1])))
Error in data.frame(c("14", "19", "01"), c("14", "20"), check.names = TRUE,  : 
  arguments imply differing number of rows: 3, 2


> dput(my_dates)
c("8/18/2011 14:19:01", "8/18/2011 14:20")

> dput(sep)
":"
# The dates in this case are really the times, but I named them 'dates' to correspond to the code within hms().
> dput(dates)
structure(c("14:19:01", "14:20"), .Names = c("c..8.18.2011....14.19.01..", 
"c..8.18.2011....14.20.."))


> sessionInfo()
R version 2.13.1 (2011-07-08)
Platform: x86_64-pc-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United States.1252    

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] stringr_0.4     lubridate_0.2.5 ggplot2_0.8.9   proto_0.3-9.2   reshape_0.8.4   plyr_1.5.2     

loaded via a namespace (and not attached):
[1] tools_2.13.1