Problem with new qexserialport 1.2beta2

[code_err]

I have a fallowing problem: after compiling my code i cannot execute program because of 0xc0000005 runtime error message. What could it be? Earlier i used qextserialport 1.1 but wanted to actualize my Qt package from 4.8.0 version to 4.8.2 version and had to recompile other, related libraries.
Anyone can help?

I also get from linker something which didn't appear before:

c:/qt/qtcreator-2.4.0/mingw/bin/../lib/gcc/mingw32/4.4.0/../../../../mingw32/bin
/ld.exe: warning: auto-importing has been activated without --enable-auto-import
specified on the command line.
This should work unless it involves constant data structures referencing symbols
from auto-imported DLLs.