Sounds like memory fragmentation...

If you use a perl version >= 5.6, try using the 5.005_03 instead. Especially for more complex hash-structures, it may use less memory, so you can create a bigger structure.

But this is just a quick hack, not a real solution; a better way may be to split up the data and try to keep only little chunks in memory. Or use a 64bit operating system... :-)

Best regards,
perl -e "s>>*F>e=>y)\*martinF)stronat)=>print,print v8.8.8.32.11.32"