Log4j - missing logs in zipped files under heavy load

Log4j - missing logs in zipped files under heavy load

We are encountering problem with log4j logging under heavy logging. We
periodically miss some logs (~4-20 minutes each 1 hour) in files, that are
rolled out and zipped.
Configuration:
<appender name="MY_LOG"
class="org.apache.log4j.appender.TimeAndSizeRollingAppender">
<param name="File" value="../logs/mylog.log" />
<param name="DatePattern" value=".yyyy-MM-dd"/>
<param name="MaxFileSize" value="40MB"/>
<param name="MaxRollFileCount" value="100"/>
<param name="ScavengeInterval" value="300000"/>
<param name="encoding" value="UTF-8" />
<param name="CompressionAlgorithm" value="ZIP"/>
<param name="CompressionMinQueueSize" value="5"/>
<param name="CompressionThreadPriority" value="1"/>
<param name="CompressionLevel" value="1"/>
<param name="CompressionUseBlockingQueue" value="true"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p %22.22t|
%22.22c{1}| %m%n"/>
</layout>
</appender>
Property "" was added as attempt to prevent logs from getting lost. We
thought (and we still do) that logs get lost while files (when there is 5
temp files) are merged and zipped. That they might get overwritten
somehow. However, this property didn't work.
I'm not sure where to look for problem, or how to change configuration, so
logs wouldn't get lost, or overwritten.
Any suggestions what we might try?
Thanks