I've gotten significantly better results with this new slicing profile. This profile is for ABS plastic. To print with PLA I use the default slicing profile, cover the build plate with painter's tape, and change the build plate temperature to 20 degrees Celsius.
I use ReplicatorG.
In ReplicatorG go to "Edit Slicing Profiles..." in the "GCode" menu.
Select "Replicator slicing defaults" and click "Duplicate..."
Enter a name for your new profile and click "Ok"
The Skeinforge Settings window will open.
Change all of your settings to match mine.
"Support Cross Hatch" is optional. Try this on or off and see which works better for the types of things you print.
When you are done changing your settings click "Save All" and close the window.
Click "Done" in the "Edit Profiles" window.
You can always edit your profile again later.
Open the file you want to print and position it on the platform.
Click "Generate GCode" and make sure that your new slicing profile is selected.
Then enter your print settings.
Object infill: 8%
Layer Height: .16mm
Number of Shells: 2
Travel Feedrate: 55
Print Temperature: 225
Before you print click the "gcode" tab.
M109 S110 T0 (set HBP temperature)
M109 S115 T0 (set HBP temperature).
[T0 uses right extruder, T1 uses left extruder]
A great reference is wiki.bitsfrombytes.com/index.php?title=Skeinforge_Raft
I have added kapton tape underneath the fans on the Makerbot Replicator. This reduces the amount of air being blown onto the print. I have taped paper over the openings on the sides of the makerbot. This helps to contain the heat.