Picklist repeats first line when scrolling (??)

Hello,

Can someone explain this to me. I have a picklist that repeats
the first line when he is on top of the table. So when i scroll
to the top of the table, it repeats the first record of the table.
It does not stop.

Also when i choose a line (so i get an other window) and i go
back by closing the window(ESC) it jumps to a different record
in the table.

I first thought it would be an index problem but even when i
reindexed the table the problem stayed. Removed all indexes to
be sure there were new ones created but it did not work. What
can this be?

Thx in advance,

Johan Lijffijt
The Netherlands