[Users] Content-Lenght problem with NOTIFYs

Hi all, a customer of ours are having some trouble with the Content-Lenght header when a NOTIFY-message goes through our OpenSER 1.2.0. Here is what seem to happend. SIP NOTIFY from our PSTN-gateway to our OpenSER: --- CUT --- Content-Length: 21. . SIP/2.0 100 Trying. . --- CUT --- SIP NOTIFY from our OpenSER to Customer: --- CUT --- Content-Length: 21. . SIP/2.0 100 Trying. --- CUT --- Now, the customer has to manually do this in his OpenSER to make the UA on his side happy: if (method=="NOTIFY") { if (search_body("SIP/2\.0 100 Trying")) { xlog("L_WARN", "R: Setting Content-Length to 20\n"); remove_hf("Content-Length"); append_hf("Content-Length: 20\r\n"); } } Please advice on what we are doing wrong here? Br, /Tobias