dpkg usage: invalid ar header

I don't seem to be able to use dpkg.  Are there issues I should know
about?  I'm probably misusing the feature, but not sure what I'm doing
wrong.

-- begin extract of broken dpkg session --

BusyBox v1.00-pre1 (2003.07.24-04:11+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

~ # cd /tmp
/tmp # wget 
http://archive.progeny.com/debian/pool/main/h/hello/hello_2.1.1-1_i386.deb
hello_2.1.1-1_i386.d 100% |*****************************| 47900 00:00 ETA
/tmp # dpkg -i hello_2.1.1-1_i386.deb
dpkg: Invalid ar header
/tmp # ar -x hello_2.1.1-1_i386.deb
/tmp # ls -l
-rw-r--r--    1 root     root          648 Jul 30 03:49 control.tar.gz
-rw-r--r--    1 root     root        47059 Jul 30 03:49 data.tar.gz
-rw-r--r--    1 root     root            4 Jul 30 03:49 debian-binary
-rw-r--r--    1 root     root        47900 Jul 30 03:49 hello_2.1.1-1_i386.deb
drwx------    2 root     root           40 Jul 30 03:43 mc-root

-- end --

-- begin extract of busybox .config --

CONFIG_AR=y
CONFIG_FEATURE_AR_LONG_FILENAMES=y
CONFIG_BUNZIP2=y
CONFIG_CPIO=y
CONFIG_DPKG=y
CONFIG_DPKG_DEB=y
# CONFIG_FEATURE_DPKG_DEB_EXTRACT_ONLY is not set
CONFIG_FEATURE_DEB_TAR_GZ=y
CONFIG_FEATURE_DEB_TAR_BZ2=y

-- end --

-- begin extract of archival/libunarchive/get_header_ar.c --

/* align the headers based on the header magic */
if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
        bb_error_msg_and_die("Invalid ar header");
}

-- end extract of archival/libunarchive/get_header_ar.c --

-- jared@xxxxxxxxxxx

"We suffer primarily not from our vices or our weaknesses, but from our
 illusions.  We are haunted, not by reality, but by those images we have put
 in place of reality." - Daniel J. Boorstin