Compressed files corrupted?

[Geno11]

Netware 6.0, SP3, NSS volumes, Sony SDT-9000.

I am having trouble with a list of compressed files. Initially, SBACKUP
could not back them up and reported the following error:

Error: (TSA600.NLM 6.0 306) A data stream cannot be opened.

Later, I found I could not open them with the application or even copy the
file. I found a reference to the problem on TID# 10071768, but that fix has
already been installed. One file, an Outlook archive file is critical.

Any ideas?
Gene Kinum
gen...@softhome.net