Cannot remove obiect.

[Soth]

Hi,
it is me again:
For some reason I cannot remove points. Those are part of object on the picture. When I am hitting Delete key nothing is happening, ctrl+x generates "Invalid argument specified" error Evantually I used sneaky (read silly) way of removing those, Model > Modify > Poly. Mesh > Filter Points and I removed all but the last one. ;(
What I am doing wrong. Those are just disconnected points; there are no polygons or edges there.
(I have noticed that sometimes I cannot delete polygon just by selecting all edges and deleting them and, for example, when I am selecting point on pyramid and deleting whole object disappears, well I should finish with triangle not just empty scene...)
Cheers
Tomek
p.s.Well I guess that only one answer to this question might be RTFM, but I am hoping that is not.

[Cryrid]

Have you tried alt+delete or ctrl+delete?

[Soth]

Thx, I found delete components which works. Assigned to Delete key (or any other), use once and XSI freezes, well not actually, I just cannot work in it anymore, cannot select/translate etc... I does actually work from alt+right click menu but not as a keystroke...
Cheers
Tomek