On "Ubuntu 14.04.2 LTS", fully up to date with a recent full reinstall of the OS, I installed the latest version of draftsight.

I can open a document, which was awesome, but the mouse lags terribly in the document viewport. It is really unusable even for viewing documents, and I was hoping to make some simple edits... :(

Suggestions on how to fix the lag?

I attempted to attach a video of the bug to the question. Notice how slow the cursor moves when in the viewport.