Yes, it's a bug. See Bug in Combobox? Thread #788447.

>Hi,
>
>I'v got a weird behaviour(baseclass) with a combobox with more than 500 records. When you use the mouse the second time to select a item, it won't work correctly but it's ok with version 6 and 7.
>
>To test: Create a cursor in the load form and put a combo with field(
>
>Form-Load:
>CREATE CURSOR wTOTO (nRecno N(5))
>FOR t=1 TO 1000
>APPEND BLANK
> REPLACE nRecno WITH T
>ENDFOR
>
>Combobox:
>.Rowsource = "wtoto.nRecno"
>.RowSourceType = 6-Field
>.Themes = .F. or .T.
>
>Will this be corrected in the soon (Hopefuly) to be release Service Pack ?
>
>Thank's in advances for those who answer.