This error is mostly result of incorrect permissions set for "ddms/android" scrips residing in "your sdk location/tools".
If you are getting only
Sending tracking request failed!
error then change the permissions assigned to "tools/android".
To do that open the directory "your sdk location/tools/" using file browser. You should see a file named android, right click-> properties -> permissions tab -> select allow executing and program. [chmod].
If your error is
Sending jdwp tracking request failed!
then you need to apply same procedure described above for "your sdk location/tools/ddms"