The settings in dinManage for VPN with "high, medium, and low" translate to the following and must match the configuration on your remote firewall exactly:
IKE
LOW=policy=phase1,lifetime=28800,dh-group=5,encryption=3des,hash=md5
MED=policy=phase1,lifetime=28800,dh-group=5,encryption=aes128,hash=sha1
HIGH=policy=phase1,lifetime=28800,dh-group=5,encryption=aes256,hash=sha1
ESP
LOW=compression=disable,lifetime=3600,mode=tunnel,pfs=enable,encryption=3des,hash=md5
MED=compression=disable,lifetime=3600,mode=tunnel,pfs=enable,encryption=aes128,hash=sha1
HIGH=compression=disable,lifetime=3600,mode=tunnel,pfs=enable,encryption=aes256,hash=sha1