Problem with http library

I’m currently working with the wip lib 1.10.02 delivered with OpenAT 4.10.10

but I have some problem using HTTP library indeed it seems to send randomly different header (HTTP/1.0 and sometimes HTTP/1.1) … What I do is :
wip_channel_t _ch = wip_HTTPClientCreateOpts(NULL,NULL,WIP_COPT_HTTP_VERSION, WIP_HTTP_VERSION_1_1,WIP_COPT_END);
int r = wip_getFileOpts(_ch, ipUdaterStr,ipPusher_event,NULL,WIP_COPT_END);

And i trace the result on my web site using tethereal … And I Got sometimes :
GET /test/CommunicationManager/IPUpdate?_id=myHttpTest&Port=80&ReqURI=dataRequestURI&Methode=0&Version=1.0 HTTP/1.1\r\n
and sometimes :
GET /test/CommunicationManager/IPUpdate?_id=myHttpTest&Port=80&ReqURI=dataRequestURI&Methode=0&Version=1.0 HTTP/1.0\r\n

Any Idea ?