Symantec Mail Security for MS Exchange - Unscannable File Rule

We have some instances where some powerpoint decks are Quarantined by mail security. Details from Event logs below. Can you please help how to make sure that these decks do not get quarantined?

Rule: Unscannable File Rule

The following actions were taken on it:

The attachment "140903 - XXXXXXXX.pptx" was Quarantined for the following reason(s):

Scan Engine Error. CSAPI DEC result: 0x11. Decomposer failed to open the container. at location oleObject1.bin within embeddings within ppt

Scan Engine Error. CSAPI DEC result: 0x11. Decomposer failed to open the container. at location oleObject2.bin within embeddings within ppt

Regards,

Navneet