NDIS 6 LWF driver indicating packets

I have NDIS 6.0 packet modifying filter driver running on Windows 7
x64. It examines outgoing TCP traffic and sometimes has to return a
packet being sent back to the protocol. For this purpose I make source/
destination address manipulations in cloned NBL and pass it to
NdisFIndicateNetBufferLists function.
The problem is that sometimes NDIS calls back my
FilterReturnNetBufferLists function and sometimes does not which
eventually leads to frozen connection. As far as I can see this
happens only for “large” packets, at least 2 times longer than MTU but
not for all of them. Is it a known problem or am I doing something wrong
when cloning?
Thank you!