Win32 API Service not responding to callbacks

[msnews.microsoft.com]

Hi All

I have a win32 dll and I am calling its functions like a win32 api calls.
There are some functions which used to set the callback from win32 service.
I am facing problem with the callbacks, some times callbacks fires properly
and some times it stops without giving any error and service doesn't
respond. I am using C# to call the win32 dll functions. I have noticed
another very interesting thing, Actually in a callback this api gives me the
byte stream (IntPtr) I write all the bytes from that stream to a file.
Previously I was transfering the data from IntPtr to a byte array then then
I was writing it to the file. When I declared the byte array service stopped
responding, interesting thing is that when I eleminated the byte array
declaration line from the code then service starts to respond. Can anyone
tell me about the reason. It is really critical to me because live data is
comming in the byte stream (IntPtr) through win32 dll callback and I have no
margin to lose any data.

I dont know when it will stop responding. Any help in this regard will be
highly appreciated. Thanks in Advance.

Take Care
Fiaz Ali Saleemi