Steps to reproduce:
1: Select cell A1
2: Press shift+Page Down (39 cells selected)
3: Press shift+Page Up (38 cells selected)
[Reproducible] with "LibreOffice 3.3.0 RC4 - WIN7 Home Premium (64bit) German UI [OOO330m19 (build 6 / tag 184.108.40.206)]".
From OOo 3.1.1 I have been used to see all cells except first one deselected in step 3 from report. In LibO the behavior of <shift>+<page up> is the same as <shifg>+<arrow up>, only 1 cell will become deselected.
My area. Great catch btw.
Luckily this was easy to fix.
Fixed on master.