When I try to convert Yabb 2.3.1 to SMF 1.1.8 I get this message:
Converting...
Successful.
Converting membergroups... Successful.
Converting members... Successful.
Converting settings...
Notice: Undefined index: userpic_width in /is/htdocs/43139/www.***/smf/yabb22_to_smf.php on line 441
Notice: Undefined index: userpic_height in /is/htdocs/43139/www.***/smf/yabb22_to_smf.php on line 442
Notice: Undefined index: userpic_width in /is/htdocs/43139/www.***/smf/yabb22_to_smf.php on line 443
Notice: Undefined index: userpic_height in /is/htdocs/43139/www.***/smf/yabb22_to_smf.php on line 444
Successful.
Converting posts (part 1 - this may take some time)... Successful.
Converting posts (part 2)... Successful.
Converting attachments (if the mod is installed)... Successful.
Cleaning up... Successful.
Converting polls and poll choices (part 1)... Successful.
Converting polls and poll choices (part 2)... Successful.
Converting poll votes... Successful.
Recalculating forum statistics... Successful.
Conversion Complete
Seems the conversion was successful (except the values of the userpic width and height), but some topics and posts have vanished into thin air.
In my YaBB:
Our users have made 68944 Posts within 1366 Topics.
We have 1153 registered members.
In my SMF:
67090 Posts in 1175 Topics by 1153 Members.
As you can see there are missing 1954 posts and 191 topics, where they're disappeared?
Next thing, I'm looking into some topics and some of the message counts are showing there are all 0 (zero). For example in YaBB is a topic with 1595 views and 590 replies, the same topic in SMF after conversion has 0 views and 590 replies. Some topics have the correct views but 0 replies although there are the right posts in the topic. I haven't a clue what's going wrong during the conversion.
Then I was looking at the memberlist and some profiles. Great surprise, all members have the same age (39) because the date of birth was set to 1. Jan. 1970

I used the yabb22_to_smf.php from here:
http://www.simplemachines.org/community/index.php?topic=249777.0and the convert.php from here:
http://www.simplemachines.org/community/index.php?topic=140741.0So what should I do? Any help would be much appreciated.