Problem with 4.54 download files?

[shuttlebox]

At one customer site their Trend http scanner is restricting me from
downloading the 4.54 files, only the sig files are allowed. I can
download the beta 4.55 files and at other sites I can download any
file. It's the zip format it's complaining about.

Message:

>>>>>
IWSS Security Event (s-iwss1)
InterScan Web Security detected the following in HTTP traffic:

Item: /files/4/tar/MailScanner-install-4.54.6-1.tar.gz
Action: deleted
Reason: Violation of a compressed file restriction

-- File: MailScanner-install-4.54.6-1.tar.gz, security warning:
Corrupted_Zip_file
The uncleanable file is deleted.
>>>>>

Why is it having problems with 4.54 but not with earlier and later releases?

-- 
/peter