Ticket #738 (closed bug: fixed)
GRASS modules lock up on attribute table access (Win32 native only)
This bug affects only native Win32 (MingW) builds of QGIS and GRASS. Any GRASS module that attempts to access attribute table data for a GRASS vector map will hang randomly. This problem is not related to any particular DBMI driver (like DBF). It has been confirmed to exist with at lease the sqlite driver, as well. You can use this sample GRASS mapset to reproduce the problem: ftp://ftp.rz.uni-kiel.de/pub/ufg/qgis-test.zip (ca. 10 MB). There is a simple vector points map in the dataset. Try exporting it using v.out.ogr a couple of times: it will hang randomly, forcing you to stop and restart the module! Since this bug spoils pretty much every GRASS vector module under, it is a real show stopper for the GRASS plugin under QGIS!
You will find more information on the GRASS developers mailing list:
And this is as far as we got hunting for the bug:
This is a really tough one, so any help will be greatly appreciated!