It didnt work in my case. The problem is one of my programs requires CTS/DSR lines to be set in HIGH state, if they are in low it just refuses to read the data on the port. AFAIK this is the requirement of the com-port specs.
Just want to say that with wine 1.1.28 I have no problems either with real serial ports or USB ones. Mind you all of my programs only need Tx & Rx. One problem that was leading me astray was that one of the bits of hardware had a crap faked Tx -ve which used a diode. This had a dry joint and the high resistance meant that it took several pulses to build up sufficient voltage :(