[Plugin: DISQUS Comment System] Can’t import comments – allowed memory exhausted

I’m trying to import my WordPress comments into Disqus. The normal Disqus plugin’s import button times out after a couple minutes, and it doesn’t show any signs of the import being in progress, regardless of whether I check via WordPress’ interface or Disqus’.

I tried to export the XML file from WordPress (to then import manually into Disqus), and I keep getting the “Allowed memory size of ……. bytes exhausted” error. Initially I only was able to export from Jan 2007 through March-ish ’07. I’ve searched through the support forum, I’ve tried increasing the memory limit via wp-config.php and wp-admin/cache.php as suggested… upped to 64M in both, got a few more months. Upped them to 128. 256. I seem to have capped out at what I can get by doing that, and it’s still only producing a 50MB file from Jan ’07 through June ’08.

Any suggestions? I have roughly 9,000 comments I need to extract.