Try dblhelper which is usually part of your CM install so just do a search on the HD or download the upgrade prep tool to 4.3 and let it do a sanity check on your CM4.1
CCMUpgdAsstInstall.4-3-4.exe
CUCM Upgrade Utility (UA),
Below is a tech note on forwarding issues
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a00801b3f4b.shtml
did you check for a Partition/calling Search Space issue?