My corporate proxy chokes on it too.

An error occurred while performing an ICAP operation: File decompression/decode error; File: CorkaMIX.zip; Sub File: No file name available; Vendor: Kaspersky Labs; Engine error code: 0x00050000; Engine version: 8.1.8.79; Pattern version: 120801.124000.8311194; Pattern date: 2012.08.01 12:40:00