3 significant firmware issues - sprinter

I have been playing with all of the various versions of acceleration firmware that have been around.

I have a 1.2 RAMPS, I have done beautiful prints on it before, but can;t help but try new stuff and sometimes it doesn't do as well.

my current issues tat I would really appreciate advice on are:

1. I can;t seem to separate out the z travel anymore. I thought this was done in the limit section of skeinforge, I think there are issues with it not going quite high enough in Z travel while printing because it's running other motors at the same time. It appears good in manual control.

2. I get some weird cut corners. I re-tightened all belts, cartesian system seems to be good, I have a fan and heatsinks on electronics etc. I get oblong circles, and very consistent corners of blocky objects that have cut corners. While printing a companion cube I can have 3 straight sides and one that is indented, and it's consistently the same one.

3. acceleration control, is there a way to simply disable acceleration? I'd love for it to be an on and off var in the firmware so I can quickly compare results.

thanks,
Anthony

1: I dunno. Are you saying that the Z axis looses steps?

2: Can you post a pic?

3: In configuration.h, set the minimum speed (default 35mm/sec, I think) to a value higher than the speed set in Skeinforge Speed module. Or, since that will likely result in skipped steps, tell Skeinforge to print slower than the minimum speed set in configuration.h.

I'm pretty new to this, but isn't your Z travel defined by your layer thickness setting?