Problem in Loading library using g++

[Hunk]

Hi
i'm using cygwin with gcc 3.4.4 and ide as RSD
I'm getting a strange error on trying to load a library using the g++
command
Here are the specifics
The library is located in the  D:\RoseTests\Myzthread\Debug
\libMyzthread.a

The option i'm using in RSD to link the library to the file is
g++  -o Concurrency.exe     nothread.o    -l"D:\RoseTests\Myzthread
\Debug\libMyzthread.a"
Note: here nothread is the object file for the cpp and Concurrency is
the project file

I'm getting the following errors

/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld:
cannot find -lD:\NGFMS\RoseTests\Myzthread\Debug\libMyzthread.a
collect2: ld returned 1 exit status

now if i use the ld command directly in the command line, it works
fine and loads the library
ld "D:\RoseTests\Myzthread\Debug\libMyzthread.a"

So wat am i doing wrong in the setting of options that gives the
error?
Any help is very welcome.