http://bugs.winehq.org/show_bug.cgi?id=17945
--- Comment #3 from Jeff Kowalczyk jtk@yahoo.com 2009-04-04 11:36:33 --- Tested on wine-1.1.11 and wine-1.1.18 ubuntu 8.10 packages. Same behaviour on both.
Regarding the native winhttp, wininet aspect, the vendor's application uses the Clever Internet suite for this functionality, and so the navtive winhttp is not used. I don't have the actual code snippet.
In this respect, the incoompatibility is with the Clever Internet Suite, not the vendor's application using it.