Check on candidates:
 
Event
Status in 98C, btag
Status in 98D, btag
Reason of reject
98C features
98D features
85393/5178
OK; -1.705
OK; -2.096
     
85688/231
OK; +1.823
NO; +4.738
5C fit prob.
   
85932/7693
OK; -2.009
NO; -2.023
electron track lost
   
88265/2411
OK; -2.537
NO; -2.648
corr. mass cut
Mj=92.5 Mee=54.3
Mj=94.0 Mee=53.3

CONCLUSION: some more work required for understanding some problem