After replicating the crash described in the bug, I found that the issue was caused by a buffer overflow in the FindReplaceDlg.cpp file. This issue was introduced when revision 196 was commited to fix a unicode display problem.
The buffer overflow occurs when handling long lines that require a resize in the buffer. The variable _uniCharLine is used when the isUnicode value is false; however, the _uniCharLine buffer is only re-allocated when isUnicode is true.
Note: Although this patch eliminated the buffer overflow, the Find result window doesn't appear to be able to handle these long lines. The line I was working with was 44270 columns, and the Find result window only appeared to scroll to somewhere around 11024 columns.