From your description of the effect it doesn't sound like something that would be expected to put a lot of demands on RAM (only 3 objects, etc.) - I wonder if one of the tracks in particular is somehow causing a problem ? Are you able to export this effect OK disabling 1 or the other of the tracks (just to try and isolate the issue)? Does the error appear right away or somewhere into the export process ?
Also, if you wouldn't mind, I would be curious to look at the Blue project file myself in Blue (I can substitute my own movie media). Could you email it to me @ firstname.lastname@example.org ?
And could you also run the OGL Hardware test from the Preview tab of the Preferences window within Blue (you can take the results from that test and copy to the clipboard for pasting and saving in a text doc or emailing)? - if you include this info in the email it will me provide some relevant system info