Currently souceforge does not offer an api to get the list of milestones that are available to a bug ticket. So for the bug report submission I have 3 choices. the first is just to leave the milestone field blank and it appears as "milestone none" in the issue tracker. the second is to allow the submitter to write down (not select) the milestone at the time of submission. this milestone has to match one of the milestones in the project otherwise a validation error is returned. The third would be to submit a bogus report with a wrong milestone. The error returned has within the message the list of milestones available. I may be able to use regular expressions to get the list of milestones.
The problems with the last approach is that one it is a hack, two is that I would have to do a bogus ticket submission every time I need the list of milestones which changes every release and three is that if sourceforge changes the way the error string is returned there is going to be a problem.