major logic error, this fixes #6 and review for #15 may be a solution for #4

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4160 43c1dc8c-776e-4df2-8ef1-6e829299be21
backport to asterisk 1.6 - 10

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4161 43c1dc8c-776e-4df2-8ef1-6e829299be21