Possible bug in 'data.table'

Manta <mantino84 <at> libero.it> writes:

Dear R users,

I may have found a bug in the function 'data.table'. I have a similar
question as the one in this post:

http://stackoverflow.com/questions/3367190/

aggregate-and-weighted-mean-in-r

[snip]

While I run the command 

temp[,list(weighted.mean(TIME3,QTY)),by=DATE2]

R crashes. This behavior occurs in both R Studio and R GUI, regardless of
the version (2.14, 2.15, 3.0). Is it really a bug or am I doing something
wrong?

If by "crash" you mean that the program actually terminates (i.e.
not just an error), then this is by definition a bug in data.table --
there is a bug tracker at 
https://r-forge.r-project.org/tracker/?group_id=240 , or you
could try contacting the package maintainer (help(package="data.table")
or maintainer("data.table")