关于DRC一个错误的问题,大家帮我分析？

我用ORCAD两个星期了,今天用DRC时遇到这样的问题...

ERROR [DRC0026]   This reference has already been assigned to a different package type. U2:  SCHEMATIC1, Signal Control  (7.60, 7.20)
ERROR [DRC0026]   This reference has already been assigned to a different package type. U8:  SCHEMATIC1, Signal Control  (7.60, 1.40)
ERROR [DRC0026]   This reference has already been assigned to a different package type. U8:  SCHEMATIC1, Signal Control  (4.30, 4.80)
ERROR [DRC0026]   This reference has already been assigned to a different package type. U2:  SCHEMATIC1, Signal Control  (7.60, 3.20)
ERROR [DRC0026]   This reference has already been assigned to a different package type. U2:  SCHEMATIC1, Signal Control  (7.60, 8.10)
ERROR [DRC0026]   This reference has already been assigned to a different package type. U8:  SCHEMATIC1, Signal Control  (4.30, 5.80)

Checking for Duplicate References

这个U2 U8都是74HC4066这个元件.画的时候是用子元件画的,开始时还没这个错,后来我用编辑元件就出这个错了,可是我没改哪里呀.

他叫我检查Duplicate References   ,我不知怎么弄,请玩过ORCAD的同仁帮我分析分析,可能是哪里出错了?谢谢...

感觉好像是说"参数已经分配了不同的封装类型".可是我都还没给他们加封装,

我英语差,不知理解是否错误?