Understanding Society User Support

Hi,

I'm working with b_indinus_xw as I'm interested in variables from the adult main interview. I'm also using as a filter b_ivfio=1 for full interviews. When carrying out analyses I get a warning message: warning #3211 which refers to the value of the weight being zero, negative or missing in some cases. Also comparing the results with and without weights gives a big difference: 50,389 valid cases against 38,788.
Reading the user guide and previous issues in the user forum I understand that in wave 1 a weight of 0 is given to temporary sample members who will not be followed in the future. Is this the case for wave 2 too? is this the reason for my warning message and the discrepancies in valid cases between results with weight and without weight? and am I justified in using this weight? I'm looking at sports and leisure activities amongst adults.
Thanks, Jen