I played more with example above and found a configuration working properly:

Log::Log4perl->init(\ qq{
    log4perl.logger               = DEBUG, A1
    log4perl.appender.A1          = Log::Dispatch::File::Locked
    log4perl.appender.A1.filename = test5.log
    log4perl.appender.A1.mode     = append
    log4perl.appender.A1.close_after_write = 1
    log4perl.appender.A1.layout   = SimpleLayout
});
[download]

Looks like the Log::Dispatch::File::Locked appender is doing better job than Log::Log4perl::Appender::File in this case.

-- Roman