Does somebody else has randomly seen crashes in ASIInputStream forwardInvocation: during the use of ASIFormDataRequest? (the request was startAsynchronous)

Here is the backtrace:

#0  0x95877b83 in CFRunLoopSourceSignal ()
#1  0x958daa45 in _CFStreamScheduleWithRunLoop ()
#2  0x9588d05d in __invoking___ ()
#3  0x9588cfc8 in -[NSInvocation invoke] ()
#4  0x958c8f28 in -[NSInvocation invokeWithTarget:] ()
#5  0x0001d7ee in -[ASIInputStream forwardInvocation:] (self=0x228d40, _cmd=0x972d80c0, anInvocation=0x225a70) at /Users/catlan/Projekte/TBU/ASIInputStream.m:75
#6  0x9588de54 in ___forwarding___ ()
#7  0x9588d982 in __forwarding_prep_0___ ()
#8  0x958da8f8 in CFReadStreamScheduleWithRunLoop ()
#9  0x958daa26 in _CFStreamScheduleWithRunLoop ()
#10 0x958daa26 in _CFStreamScheduleWithRunLoop ()
#11 0x00015d4d in -[ASIHTTPRequest scheduleReadStream] (self=0x2318e0, _cmd=0x23490) at /Users/catlan/Projekte/TBU/ASIHTTPRequest.m:2608
#12 0x0000de97 in -[ASIHTTPRequest startRequest] (self=0x2318e0, _cmd=0x23827) at /Users/catlan/Projekte/TBU/ASIHTTPRequest.m:1005
#13 0x0000b56c in -[ASIHTTPRequest main] (self=0x2318e0, _cmd=0x973cfd56) at /Users/catlan/Projekte/TBU/ASIHTTPRequest.m:624
#14 0x0000b0a8 in -[ASIHTTPRequest startAsynchronous] (self=0x2318e0, _cmd=0x2136e) at /Users/catlan/Projekte/TBU/ASIHTTPRequest.m:546
#15 0x00004b0f in -[TBUploadWindowController requestUserInfo] (self=0x2f09e10, _cmd=0x205ed) at /Users/catlan/Projekte/TBU/TBUploadWindowController.m:119
#16 0x92591ad9 in __NSFireDelayedPerform ()
#17 0x95851edb in __CFRunLoopRun ()
#18 0x9584f864 in CFRunLoopRunSpecific ()
#19 0x9584f691 in CFRunLoopRunInMode ()
#20 0x908fdf6c in RunCurrentEventLoopInMode ()
#21 0x908fdd23 in ReceiveNextEventCommon ()
#22 0x908fdba8 in BlockUntilNextEventMatchingListInMode ()
#23 0x96b4eac5 in _DPSNextEvent ()
#24 0x96b4e306 in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] ()
#25 0x96b1049f in -[NSApplication run] ()
#26 0x96b08535 in NSApplicationMain ()
#27 0x00002c8c in main (argc=1, argv=0xbffff858) at /Users/catlan/Projekte/TBU/main.m:13

Any idea on how to debug this?