This script concatenates multi-line messages, printing them as it goes.

use strict;
use warnings;

my $buffer = q();

while(<DATA>)
{
    chomp;
    if(/KB[0-9]/)
    {
        $buffer .= $_;
    }
    else
    {
        print "$buffer\n" if $buffer;
        $buffer = $_;
    }
}
print "$buffer\n";

__DATA__
"Information","17","4/13/2006 12:54:25 PM","Windows Update Agent","ISA
+","Installation","N/A","Installation Ready: The following updates are
+ downloaded and ready for installation. To install the updates, an ad
+ministrator should log on to this computer and Windows will prompt wi
+th further instructions:
- Security Update for Windows Server 2003 (KB911562)
- Windows Malicious Software Removal Tool - April 2006 (KB890830)
- Cumulative Security Update for Internet Explorer for Windows Server 
+2003 (KB912812)
- Security Update for Windows Server 2003 (KB908531)
- Cumulative Security Update for Outlook Express for Windows Server 20
+03 (KB911567)"
"Information","17","4/13/2006 12:54:19 PM","Windows Update Agent","ISA
+","Installation","N/A","Installation Ready: The following updates are
+ downloaded and ready for installation. To install the updates, an ad
+ministrator should log on to this computer and Windows will prompt wi
+th further instructions:
- Security Update for Windows Server 2003 (KB911562)
- Windows Malicious Software Removal Tool - April 2006 (KB890830)
- Cumulative Security Update for Internet Explorer for Windows Server 
+2003 (KB912812)
- Security Update for Windows Server 2003 (KB908531)"
[download]

I hope it is of use.

Cheers,

JohnGG

Update:

I looked at this again and wondered how it was printing the last log message when I had forgotten to do a final print statement after the while loop. It was working because there was a blank line at the end of the __DATA__ file (I nearly said Data Division thus revealing a murky COBOL past).

Code now corrected.