Openshot 1.4.3 in ubuntu 14.04

G'day all. I recently started using openshot 1.4.3 for home video edits. I use a HC-V520 Panasonic camcorder and shoot in HD, dimension 1920 x 1080, 25 fps. I'm using a Lenovo G510 laptop with the following :
Memory; 3.8 GiB,
Processor; Intel® Core(TM) i5-4200M CPU @ 2.50GHz × 4,
Graphics; Intel® Haswell Mobile
Os type; 64-bit
Disk space; 839,8 GB

System requirements for Openshot seem to be the following;

Operating System: Linux
RAM: 0.256GB
Hard Disk Drive: 1GB
Processor: 600MHz
Python, GStreamer, gtk+, GooCanvas, MLT Framework.

PROBLEMS.
When I start a new project, all seem to go well but as soon as the total amount of file space reaches around the 1 Gig mark, Openshot becomes erratic. Adding new files cause the screen to go black and white for a few seconds then clears again. Sometimes the pointer line just jumps back to the starting point, there are long pauses between commands, fps rates change unsynching audio and video, or it will just shut down. I used System monitor to check usages during operation and noticed that during uploads of new files one of the four CPU's will peak at 100% during which time the screen also goes into grey mode. Its normally after this that the trouble starts.
Now, with totally infantile knowledge of computers, even I can understand that if the software requires 0.256 Gig of ram and 600 MHz and I offer it 3.8 Gig ram and a choice of four 2.5GHz CPU's, something does not gel.
I really like Openshot and would really appreciate assistance in this regard.
Thanks