Hi everybody,
I am relatively unexperienced Inkscape user, but I like it a lot. Sometimes I open it just for fun.

Today i was "vectoring" a logo, like few times before. I used Bezier curve tool, but after finishing the curve, it doesn't show curves, but straight lines between points i made. It also shows "hand" when I move mosue over the line, so I can move it, but the picture doesn't move. If I release that curve somewhere nearby, I can still see the line straight between points, but the "hand" on my mouse shows, when I move over the new position, not over the "visible image". Seems like I've changed something about displaying, but I was not changing anything.

Additional info:
If happened few more times today and yesterday. Yesterday I thought I should update Inkscape, but it didn't help. So now I'm on latest one - 0.48, using it's Slovak translation on English Windows 7 Ultimate. I should also mention that I have dual monitor - 15'' notebook and 19'' LCD. Last time it happened, i changed the type of verticles few times and it fixed itself, but now it does not.
I am sorry if it was already asked/answered, but I haven't found it.

Thank you very much.

Welcome to InkscapeForum!

Hhm, it's hard to say. Could you provide the SVG file? Then we can download it an examine the file. Sometimes it's easier than asking so many questions. You can attach to a reply message (look below Submit button for Upload Attachment tab), or upload any place you prefer.

It sounds like there's a nearly transparent path above the one you see, which seems unusual. So it would really help to see the file. Or maybe the layer is locked?? Or you're on the wrong layer?? Really hard to say though, without seeing the file.

Thanks for warm welcome, meanwhile i reinstalled Inkscape because it was doing always. Now it works fine on new files, but I have preserved one faulty, that is still going bad. It's attached. I was learning vectorisation on Wordpress logo, but after putting down straight lines, I was able to move them, but it didn't showed as moved.

I see the problem in example.svg file. But it is a problem which I don't know the cause or the fix.

You can grab the black path with the Node tool, and drag it to the side, but the path doesn't move. You can even search around later, with the Node tool, and locate the apparently invisible path, because the little hand flashes when the mouse/pointer crosses it. The original path appears not to have changed, but you can no longer grab it from its original location. Very strange problem!

Hopefully someone else will have some ideas?

Edit
Sometimes the path will sort of jump around while you're dragging it, but it's not behaving as it should, even then. They resemble vaguely spiro splines, or as if they had auto-smooth nodes. But not entirely.

Oh, oh, oh! I believe you may have drawn the path with the Pen tool in spiro mode, because the info area reports "path effect, Spiro Spline". But I don't think that explains the part where you drag the path, but it doesn't appear to move.

Well now I've done a test in a new document. And yes, that's exactly how the path behaves, if you draw it with the Pen tool in spiro mode. You can grab the path and drag it a short way. It doesn't move. But if you then search around in the area where you released the mouse, you can see the little hand flashing when you cross the apparently invisible path. I don't know if that might be a bug, or if it's somehow supposed to behave like that?

But the bottom line is that when you engage the Pen tool, look at the tool control bar, and be sure to click "Create regular Bezier path" (and Shape: None). Or you could use any of the modes except for Spiro, to draw regular paths. I actually prefer to use "Create sequence of straight line segments" because if I accidentally drag the mouse when I click to place a node, it will place a smooth node instead of a cusp/corner node. And using 'straight line segments' prevents that.

Anyway, it's the spiro mode that's causing your problem. If you did a clean install of Inkscape, it set your Pen back to regular bezier mode, and that's why reinstalling appeared to fix it. But just be mindful of the tool control bar. There's a lot to learn with Inkscape. It's deceptively simple at first, but I find myself still learning more almost every day, and this is after 4 or 5 years using Inkscape!

Thank you very much for quick research. I wanted to ask one last question, but I figured it out. The question was, if it's possible to transform that "Spiro path" to normal.

Answer is: Open Path effect editor, select the path and remove the Spiro spline effect.

Thank you brynn for helping me

Ah yes, that would work too