Dragging sometimes has momentary bounceback

[Formerly Kevin Yin, now disabled]

I'm using the Intel i3-2300m. Specifically, that means my graphics card is the Intel HD3000, which is equivalent to a very low-end AMD or Nvidia discrete graphics card. This may or may not affect reproduction of the bug.

To reproduce:
Draw a rectangle.
Using the select tool, drag the rectangle slowly to the left.

The rectangle will occasionally wiggle a bit by moving too far to the left, and then move back to the right (at least, that's what I think I see, it's hard to tell).

[su_v (suv-lp)]

> I'm using the Intel i3-2300m

- Which OS, which Inkscape version (see Inkscape menu 'Help > About Inkscape')?

> The rectangle will occasionally wiggle a bit by moving too far to the left,
> and then move back to the right (at least, that's what I think I see, it's
> hard to tell).

- Any processes in the background which temporarily compete with Inkscape for CPU resources?
- Is this in a default new document based on the default template, or did you have grid and snapping (e.g. to grid) enabled in the current document when testing for this report?
- Does it also happen with default (reset) preferences? More specifically, did you change (lower) the preference setting for numeric precision (default: 8) which would effect (readjust) the position after releasing the grab?

[Formerly Kevin Yin, now disabled (kyin)]

Sorry, i3-2100m, HD3000. 2300m was wrong. Inkscape 0.48.2 r9819 on Windows 7 x64.
Total background CPU usage is consistently 0%.
I used a new document; it might be the default template. I don't know how to change the default template. There's no grid, and snapping is off.
Numeric precision is 8.
I don't see where I can reset my preferences and default template.

I'm having trouble reproducing this; sometimes it works and sometimes it doesn't.

[su_v (suv-lp)]

> I used a new document; it might be the default template. I don't know how to change
> the default template.

In this case the new document is based on the default template, yes.

> I don't see where I can reset my preferences and default template.

1) Preferences
To reset the preferences, quit Inkscape and rename the preferences file [1]:
%APPDATA%\inkscape\preferences.xml

2) Templates
The default template (for all users) is inside 'share\templates\' in Inkscape's program folder: better not to change it (usually). You can work with user template files which can be used to override the shared default template: if interested, you'll find an excellent introduction to working with templates in Inkscape here:
<http://libregraphicsworld.org/blog/entry/using-templates-in-inkscape>

User templates on Windows are loaded from:
%APPDATA%\inkscape\templates\

---
[1] You can copy and paste the paths from above directly into Explorer's address bar (it will resolve the variable %APPDATA% for you), or look up the default paths e.g. here: <http://en.wikipedia.org/wiki/Environment_variable#Default_Values_on_Microsoft_Windows>

[Formerly Kevin Yin, now disabled (kyin)]

The screen resolution for the original bug was 1366x768.

On a 1600x900 monitor with the Intel HD4000, I can also see this bug.

It's clear that the rectangle isn't moving too far to the left. Instead, it is occasionally showing positions to the right: old positions are being briefly rendered after new positions have already appeared. This causes the bouncing effect.

Imagine UDP packets arriving out-of-order, so that an old packet overrides a new packet's information. That's what I'm seeing here, but with framebuffers instead of packets.

[jazzynico (jazzynico)]

Reproduced on Windows XP, Inkscape trunk rev. 14020, 0.48.5 and 0.47.
Only happens when snapping is enabled (even if all the other snapping icons are unchecked). Dragging works smoothly when disabling snapping.