The second was that the form used "jr:count=" for a repeat and referenced a node that had no answer entered when the user tried to save. This is actually a bug in javarosa. The workaround is to make that group relevant only if the node referenced by jr:count is greater than 0. the relevance check properly handles the empty answer case, jr:count does not. This bug also causes a crash when trying to use the "jump to" feature, and the workaround also fixes the "jump to" case.
Issue #58 new