Crash when attempting to extract

It seems i can not longer extract from zip files. Betterzip crashes. This is what i found in the Console:

16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Downloads/.BetterZipTempFolder_00254bb43a4c_2010-01-16 14:35:04 +0100/ to the trash. Error 2
16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Downloads/.BetterZipTempFolder_00254bb43a4c_2010-01-16 14:29:52 +0100/ to the trash. Error 2
16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Downloads/.BetterZipTempFolder_00254bb43a4c_2010-01-16 14:24:15 +0100/ to the trash. Error 2
16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Downloads/.BetterZipTempFolder_00254bb43a4c_2010-01-16 13:05:43 +0100/ to the trash. Error 2
16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Library/Audio/Sounds/Alerts/.BetterZipTempFolder_00254bb43a4c_2010-01-15 07:07:46 +0100/ to the trash. Error 2
16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Downloads/.BetterZipTempFolder_00254bb43a4c_2009-12-30 11:39:36 +0100/ to the trash. Error 2
16.01.10 14:37:12 BetterZip[1507] couldn't move /Users/olaf/Projects/.BetterZipTempFolder_00254bb43a4c_2009-11-15 17:01:16 +0100/ to the trash. Error 2
16.01.10 14:37:16 BetterZip[1507] *** WARNING: Method selectedRowEnumerator in class ZipOutlineView is deprecated. It will be removed in a future release and should no longer be used.
16.01.10 14:37:18 BetterZip[1507] An uncaught exception was raised
16.01.10 14:37:18 BetterZip[1507] *** -[NSURL initFileURLWithPath:]: nil string parameter
16.01.10 14:37:18 BetterZip[1507] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSURL initFileURLWithPath:]: nil string parameter'
*** Call stack at first throw:
(
0 CoreFoundation 0x940e240a __raiseError + 410
1 libobjc.A.dylib 0x93aba509 objc_exception_throw + 56
2 CoreFoundation 0x940e2138 +[NSException raise:format:arguments:] + 136
3 CoreFoundation 0x940e20aa +[NSException raise:format:] + 58
4 Foundation 0x92145bf4 -[NSURL(NSURL) initFileURLWithPath:] + 90
5 Foundation 0x92145b82 +[NSURL(NSURL) fileURLWithPath:] + 72
6 BetterZip 0x0000f209 -[AHandler7ZipBase extract:toFolder:password:command:params:] + 584
7 BetterZip 0x00024d42 -[ZipDocument _extract:toFolder:extractedSize:saving:] + 877
8 BetterZip 0x000257ba -[ZipDocument extract:] + 737
9 AppKit 0x91a01889 +[NSApplication _startDrawingThread:] + 78
10 Foundation 0x921108d8 -[NSThread main] + 45
11 Foundation 0x92110888 __NSThread__main__ + 1499
12 libSystem.B.dylib 0x95da2fbd _pthread_start + 345
13 libSystem.B.dylib 0x95da2e42 thread_start + 34
)
16.01.10 14:37:19 com.apple.launchd.peruser.502[838] ([0x0-0xc00c0].com.macitbetter.betterzip[1507]) Job appears to have crashed: Trace/BPT trap
16.01.10 14:37:19 ReportCrash[1514] Saved crash report for BetterZip[1507] version 1.8.3 (1.8.3) to /Users/olaf/Library/Logs/DiagnosticReports/BetterZip_2010-01-16-143719_MacMini.crash

The system is a german Mac Os X 10.6.2. This happens for some time now, maybe since upgrading to Snow Leopard, but i'm not sure about this. It makes no difference to extract by DnD to a finder window or by using the extract dialog.