Incorrect content identification

[Kiss Gabor (Bitman)]

Dear folks,

A few times a week I find amavis logs like these:

Oct 19 21:02:23 cirkusz amavis[5594]: (05594-20-2) (!)Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes
Oct 19 21:02:23 cirkusz amavis[5594]: (05594-20-2) NOTICE: Virus scanning skipped: Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes
Oct 19 21:02:26 cirkusz amavis[5594]: (05594-20-2) (!)NOTICE: HOLD reason: Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes
Oct 19 21:02:26 cirkusz amavis[5594]: (05594-20-2) (!)Inserting header field: X-Amavis-Hold: Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes


Oct 19 21:24:12 cirkusz amavis[8906]: (08906-12) (!)Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes
Oct 19 21:24:12 cirkusz amavis[8906]: (08906-12) (!)NOTICE: HOLD reason: Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes
Oct 19 21:24:12 cirkusz amavis[8906]: (08906-12) (!)Inserting header field: X-Amavis-Hold: Exceeded storage quota 314572800 bytes by do_pax_cpio/pre; last chunk 347994408774 bytes


Oct 20 09:55:15 cirkusz amavis[4330]: (04330-13) (!)Exceeded storage quota 37142500 bytes by do_pax_cpio/pre; last chunk 21475580275 bytes
Oct 20 09:55:15 cirkusz amavis[4330]: (04330-13) NOTICE: Virus scanning skipped: Exceeded storage quota 37142500 bytes by do_pax_cpio/pre; last chunk 21475580275 bytes
Oct 20 09:55:19 cirkusz amavis[4330]: (04330-13) (!)NOTICE: HOLD reason: Exceeded storage quota 37142500 bytes by do_pax_cpio/pre; last chunk 21475580275 bytes
Oct 20 09:55:19 cirkusz amavis[4330]: (04330-13) (!)Inserting header field: X-Amavis-Hold: Exceeded storage quota 37142500 bytes by do_pax_cpio/pre; last chunk 21475580275 bytes


These mails actually do not contain any pax or cpio archives.
So I do not understand what happens here... :-(
Any idea what to check?

Amavisd-new is installed from a Debian package version 1:2.6.4-3.

Thanks

Gabor