I am running QGIS v. 1.8 on both my Windows and Mac partitions; Every time I try to open a jpeg2000 (jp2) raster on the mac version the program locks up and I need to force quit.
Does anyone have any ideas how to fix this problem?
I don't know what causes the program to lock, but I'd guess that the jpeg2000 files use a compression not supported by the GDAL build that your OS X QGIS uses. Some .jp2 files use compression formats (MrSID, EVW or Kakadu) that are not supported by open source libraries. GDAL Raster Formats contains an overview of the different jp2 formats and what libraries GDAL has to link against to support each.
You probably could use gdal-config (maybe
--dep-libs) to check if there are differences between the versions installed in Windows and OS X.
If you use the KyngChaos build of QGIS and GDAL you can get plugins for MrSid and ECW here, which might solve the problem.
Though it'd still be a bug that opening an unsupported jpeg2000 file causes QGIS to freeze.
If this is not an issue with the jpeg2000 driver in GDAL I have no clue.