i agree with renate... i've played several very successful TA alliances both as A and T... and I've played several where it went down hill fast. usually the best TA is when you have an equivelant EF and end it in a 4way draw... but otherwise, it is likely to end in blows to the detriment of Austria.
however, as Austria, sometimes you dont have a choice - a non-responsive Russia and an inept italy almost force your hand you just have to keep units at home...
but in my experience for the alliance to work, T needs to get Gre, Sev, and most of italy/tunis while Austria gets Rum/Bul/Ser... so at some point, you'll have to swap Gre for Bul... with the understanding that T can only have fleets in Gre. as time progresses, you can also try to dmz Aeg... and potentially A parking his fleet in Adr. this avoids most of the problems... but still more unstable than any other alliance on the board.
this is why i dislike Turkey so much... the relationship with Austria is written off by so many ppl, and any solid alliance with Russia has to be so hidden so that people dont get scared of the Jugg... and its so difficult to work with italy unless you promise to build zero fleets (or limit to one) so in essence, turkey's choices are so limited and if any of your neighbors are bad players or just novices, its even tougher.
long story short - if you can get the AT to work, it is to you benefit, so its worth the extra effort - as most people dont expect it and cant respond well to it, and it eventually gives T the upper hand.