confusing error using .NET C++

[Al Havrilla]

i'm getting the following error from my DEBUG build of a
program that ran fine under vc 6.

---------------------------------

ntdll.dll!77f75 a58()
ntdll.dll!77f9c b5e()
ntdll.dll!77f82 c95()
KERNEL32.DLL!77 e75b6c()
KERNEL32.DLL!77 e6c75a()
cs.exe!_CrtIsVa lidHeapPointer( const void *
pUserData=0x010 3f8c8) Line 1807 C
cs.exe!_free_db g_lk(void * pUserData=0x010 3f8c8, int
nBlockUse=1) Line 1132 + 0x9 C
cs.exe!_free_db g(void * pUserData=0x010 3f8c8, int
nBlockUse=1) Line 1070 + 0xd C
cs.exe!operator delete(void * p=0x0103f8c8) Line 369 +
0xb C++
cs.exe!RxPacket <60>::`scalar deleting destructor'() +
0x20 C++
cs.exe!CommPort ::releaseWhosTh ereRxPacket() Line 137 +
0x2b C++
cs.exe!CommPort ::waiting_on_wh os_there_query( ) Line 308
C++
cs.exe!CommPort ::run() Line 600 C++
cs.exe!CommEngi ne::commThread( void * pParam=0x000000 00)
Line 98 C++
cs.exe!_AfxThre adEntry(void * pParam=0x0012fa 8c) Line
114 + 0xd C++
cs.exe!_threads tartex(void * ptd=0x01037558) Line 241 +
0xd C
KERNEL32.DLL!77 e7d33b()

----------------------------------

any help would be greatly appreciated. the pointer in
question is "newed" by a worker thread then "deleted" by
the same thread .... so seems to me it should be using
the "local heap".

thanks,
Al