Importing attachments not working on Dreamhost

I’ve just emancipated my blog from wp.com, and Dreamhost does a great job with the one-click installs.
I thought I didn’t have a chance to transload all the images, but the “import attachments” caught my breath after uploading the xml file. All my happiness went away though as it returned an ungraceful 500 error after several seconds loading. Without enabling it, the import works just fine.

Is there anything I can do to set my hosting up to whatever www.remarpro.com is doing while attempting to transload all attachments?

Btw, I’m using the one-click advanced mode, so I’ve got good access to db, filesystem, some CGI settings, etc. Any clue to what could be causing this would be very appreciated!