Hello Claudia,
today I have find a solution for your problem !
You must download the new postgresql version 7.3.4-2.
I use the following packages:
cygwin 1.5.1-1
cygipc 2.01-2
postgresql 7.3.4-2
Download the file cygpopt-0.dll.zip from http://gray-world.net/projects/cctt/win32_cctt/ and copy the unpacked file in the directory /bin.
Now you can use ipc-daemon2 and initdb correctly.
Have fun
Alfred Kottek
EMail: ak(at)akottek(dot)de