Nightly crashes after reading file from Sibelius

1) Enter 2 pages of Bach into Sibelius 2.3
2) Read resulting .sib file with Sibelius 6.1
3) Export as MusicXML(attached) with Dolet 6
4) Open MusicXML with MuseScoreNightly-r5512 --> crash

Last Console messages were:
01/04/12 12:25:20 [0x0-0x11e51e4].net.sourceforge.mscore[13310] MuseScore::importMusicXml() return true (OK)
01/04/12 12:25:21 mscore[13310] *** __NSAutoreleaseNoPool(): Object 0x236038c0 of class NSConcreteMapTable autoreleased with no pool in place - just leaking

Thanks for the good work - nice talking to you at Fosdem recently.