SSRN--A valuable resource, but is it compatible with exclusivity?

Many of our readers may not be aware of this resource, but in the world of legal academia, we have become familiar with a service called the Social Science Research Network, or SSRN.  The SSRN site is essentially a clearing house of scholarship (abstracts, working papers, accepted papers, and finished articles with publisher permission) in all areas having to do with social science.  The law-related papers are housed in the Legal Scholarship Network, and within that network, there is a category for education law scholarship. You can use this site to keep abreast of the most recent work in the education law field.

I just updated my most recent piece, forthcoming in the Alabama Law Review, on the site.  The abstract is here, and as with most articles included in SSRN's database, you can download the full text of the current version (All rights are reserved, of course) by using the link at the top of the page.  Downloads of pieces from SSRN are usually free, but you have to register for the service (also free).  Once registered, you can just search for the articles and working papers that interest you, or you can "subscribe" to certain subject matter services (such as the Education Law service), which will mean that you will receive the articles for that category in your email inbox.  SSRN calls these "e-Journals," but they are more like listserves and clearing houses.  Some of these "subscriptions" cost money, though, so manual searching may be the way to go. 

Not only is SSRN very useful for those who want to keep abreast of scholarly trends, but it is also very helpful to academics and other scholarly writers who want to ensure a broad dissemination of their work.  I am interested to know, though, whether the peer-reviewed, exclusive-submission journals most common for tenure articles in fields other than law would have a problem with one "publishing" one's working draft on SSRN.  My intuition says that they would consider the submission non-exclusive or previously published once it was placed on SSRN, but I may be wrong.  This interpretation, I feel, would be unfortunate from the perspective of scholarship dissemination and knowledge building.  Thoughts from editors (and anyone else who might know the answer) are welcome in the comments.