Looping stutters

I am trying the demo.Thus far MIDI only, using MIDI Mapper, which is driected to a Yamaha SYXG50 softsynth.

I have been doing MIDI for many years, but stopped a couple of years back for various reasons. What may be catching me is the complexity of the later programmes’ interfaces etc.

At present I have a 27 Ghz machine with 512Mb RAm and I am running XP Home; MOBO video card and a MOBO sound card. I am OK with getting latency etc from these, but the stuff I am trying is really simple. I am trying to decide whether to get back into music making, so I need to ask these questions before I start laying out money.

I guess my question is: Is anyone sel seeing these problems, or do I go out and get a better video/audio card.

Slight pause during looping
the loop seems to “overrun” the end of the loop randomly. This causes a pause, and also sometimes includes the next note after the end of the loop
this is worse with MIDI Mapper to drums, but also happens erratically with say, the DaHronet synth
it may be connected that when I press the “Stop button” I usually get an exatr nite before it stops playing.

So. Any help appreciated