Command failure: Too Many Files (rm, ls, tar)

I have a directory that has grown quite large (over 2500 files).

I regularly copy the files to a transfer directory, cd to that
directory, and tar them and gzip them (tar cvzf xfer.tgz *) to take them
to another site.

Last week I started getting errors indicating there were too many files
for the command (rm *, ls *, tar cvzf xfer.tgz *) to continue.

I was able to get the commands to work by reducing the file count down
to about 1900.  Is there a magic number limit on those commands?  Or am
I doing something wrong.  I'm currently running linux on an Intel PC
with a Fedora 7 distribution.

Thanks.

-Tom