[Chaosu]

I'm using ImgBurn for burning my dvds. Lately I'm getting bad results. My burner (device) buffer is floating instead of keeping 99%/100% full as it was before, memory buffer is sometimes going down to 0% and the I'm getting errors, burning paused and 'waiting for buffers to recover' and later 'waiting for hard disk to reach thershold(?) level which go immediately'. I checked checksums (on different disks) and all were ok but I'm experiencing kind of glitch during playback... it 'froze', there is no skip with music or video, but it stops. I'm confused, my computer is not too good and I can't tell if it is because of bigger data stream (so depends on video) but video is burned ok or perhaps it's on video as downloaded or it's caused by mentioned burning error.
Any help?

-edit-
Forgot to mention, burning speed never exceed 1,4x (sometimes slow down to 0,6x) and I used 4x previously (it's set on 4x still).