http://bugs.winehq.org/show_bug.cgi?id=3891
------- Additional Comments From alaeddinaydiner@yahoo.com 2005-20-11 11:26 ------- It is probably true that wine developers did not make the mistake of trivially forgetting to close file descriptors, but the application might be reopening the com device repeatedly without closing it.
Thus, when a com device is reopened, the fix might be to close earlier file descriptors to it by the same thread/process, if there are any. It looks like windows closes com devices when they are reopened as well.
Alaeddin.