Glitchy Crackling Sound -- Any Ideas?

[Movies]

I recently picked up a copy of Miroslav Philharmonik and have been running it with DP 6.03 on a [normal] macbook with 2GB of RAM -- recording onto a 7200 RPM external hardrive through a PreSonus Firepod.

For some reason -- just with Miroslav -- I get this weird digital-sounding crackle, primarily in the right channel, in both my speakers AND my headphones.

I can't recreate this business in any other way -- loading a normal project file with DP instruments AND/OR running DP with Reason is fine.

The moment that Miroslav enters the picture, though, it starts.

I'd appreciate any thoughts y'all have on the matter.

Thanks!