error during auto merge segment

I encounter this error halfway through indexing my email messages. After about 
10000 docs in the index.

My current quick hack is to remove the 
        #       $self->_maybe_merge_segments;
call in Plucene/Index/Writer.pm, and do $writer->optimize at the end.


==============================
SIZE IS 0 at /usr/local/lib/perl5/site_perl/5.8.1/Plucene/Index/SegmentTermEnum.
pm line 74
        Plucene::Index::SegmentTermEnum::new('Plucene::Index::SegmentTermEnum','
Plucene::Store::InputStream=ARRAY(0x9c8be34)','Plucene::Index::FieldInfos=HASH(0
x9d12f48)',0) called at /usr/local/lib/perl5/site_perl/5.8.1/Plucene/Index/TermI
nfosReader.pm line 52
        Plucene::Index::TermInfosReader::new('Plucene::Index::TermInfosReader','
/tmp/3oxy8Bf8qB','_10894','Plucene::Index::FieldInfos=HASH(0x9d12f48)') called a
t /usr/local/lib/perl5/site_perl/5.8.1/Plucene/Index/SegmentReader.pm line 82
        Plucene::Index::SegmentReader::new('Plucene::Index::SegmentReader','Pluc
ene::Index::SegmentInfo=HASH(0x9cd0e40)') called at /usr/local/lib/perl5/site_pe
rl/5.8.1/Plucene/Index/Writer.pm line 274
        Plucene::Index::Writer::_merge_segments('Plucene::Index::Writer=HASH(0x9
b1580c)',24) called at /usr/local/lib/perl5/site_perl/5.8.1/Plucene/Index/Writer
.pm line 253
        Plucene::Index::Writer::_maybe_merge_segments('Plucene::Index::Writer=HA
SH(0x9b1580c)') called at /usr/local/lib/perl5/site_perl/5.8.1/Plucene/Index/Wri
ter.pm line 155
        Plucene::Index::Writer::add_document('Plucene::Index::Writer=HASH(0x9b15
80c)','Plucene::Document=HASH(0x9d12b84)') called at /usr/local/lib/perl5/site_p
erl/5.8.1/spm/search_plucene.pm line 120

===========================

regards,
kiat