Amverify error

I get this error every night. I have seen that several people have been getting the same errors but I still don't quite understand why I am recieving them. This looks like the culprit:

gzip: stdin: invalid compressed data--crc error

gzip: stdin: invalid compressed data--length error

Can anyone tell me why this is happening.

Thank you,
David

Tapes:  Northland_Regular04
Errors found: 
Northland_Regular04 (mail.datajunction.com._.20030914.0):
amrestore: WARNING: not at start of tape, file numbers will be offset
amrestore:   0: restoring mail.datajunction.com._.20030914.0

gzip: stdin: invalid compressed data--crc error

gzip: stdin: invalid compressed data--length error
amrestore:   1: reached end of information
/bin/gtar: Skipping to next header
/bin/gtar: Archive contains obsolescent base-64 headers
/bin/gtar: Error exit delayed from previous errors
64+0 in
64+0 out
Northland_Regular04 (web.datajunction.com._.20030914.0):
amrestore: WARNING: not at start of tape, file numbers will be offset
amrestore:   0: restoring web.datajunction.com._.20030914.0

gzip: stdin: invalid compressed data--format violated
Error 32 (Broken pipe) offset 257130496+32768, wrote 0
amrestore: pipe reader has quit in middle of file.
/bin/gtar: Unexpected EOF in archive
/bin/gtar: Error is not recoverable: exiting now
64+0 in
64+0 out
Northland_Regular04 ():
amrestore: WARNING: not at start of tape, file numbers will be offset
** No header
0+0 in
0+0 out
Northland_Regular04 (webdev.datajunction.com._.20030914.0):
amrestore: WARNING: not at start of tape, file numbers will be offset
amrestore:   0: restoring webdev.datajunction.com._.20030914.0

gzip: stdin: invalid compressed data--crc error

gzip: stdin: invalid compressed data--length error
amrestore:   1: reached end of information
/bin/gtar: Skipping to next header
/bin/gtar: Archive contains obsolescent base-64 headers
/bin/gtar: Archive contains `\023yêáªÔXEò\233NÕ' where numeric off_t value expected
/bin/gtar: Skipping to next header
/bin/gtar: Error exit delayed from previous errors
64+0 in
64+0 out

amverify Northland_Regular
Mon Sep 15 12:20:35 CDT 2003

Using device /dev/nst0
Volume Northland_Regular04, Date 20030914
Checked nexus.datajunction.com._.20030914.0
** Error detected (mail.datajunction.com._.20030914.0)
amrestore: WARNING: not at start of tape, file numbers will be offset
amrestore:   0: restoring mail.datajunction.com._.20030914.0

gzip: stdin: invalid compressed data--crc error

gzip: stdin: invalid compressed data--length error
amrestore:   1: reached end of information
/bin/gtar: Skipping to next header
/bin/gtar: Archive contains obsolescent base-64 headers
/bin/gtar: Error exit delayed from previous errors
64+0 in
64+0 out
Checked localhost._.20030914.0
** Error detected (web.datajunction.com._.20030914.0)
amrestore: WARNING: not at start of tape, file numbers will be offset
amrestore:   0: restoring web.datajunction.com._.20030914.0

gzip: stdin: invalid compressed data--format violated
Error 32 (Broken pipe) offset 257130496+32768, wrote 0
amrestore: pipe reader has quit in middle of file.
/bin/gtar: Unexpected EOF in archive
/bin/gtar: Error is not recoverable: exiting now
64+0 in
64+0 out
** Error detected ()
amrestore: WARNING: not at start of tape, file numbers will be offset
** No header
0+0 in
0+0 out
** Error detected (webdev.datajunction.com._.20030914.0)
amrestore: WARNING: not at start of tape, file numbers will be offset
amrestore:   0: restoring webdev.datajunction.com._.20030914.0

gzip: stdin: invalid compressed data--crc error

gzip: stdin: invalid compressed data--length error
amrestore:   1: reached end of information
/bin/gtar: Skipping to next header
/bin/gtar: Archive contains obsolescent base-64 headers
/bin/gtar: Archive contains `\023yêáªÔXEò\233NÕ' where numeric off_t value expected
/bin/gtar: Skipping to next header
/bin/gtar: Error exit delayed from previous errors
64+0 in
64+0 out
End-of-Tape detected.