Latin diphthongs

Can there be diphthongs spanning root and case ending, i.e., are meus and meum one syllable words while mea is a two syllable word?
Also, can there be diphthongs where one or both vowels are long? Take for example the genitive of meus, mei (long i). How would that be pronounced?

>are meus and meum one syllable words

No, they're two syllables, at least under British/American pronunciation.  (A different system of Latin pronunciation is taught in Continental Europe, which I am not familiar with.)

"Mea", "meus", "meum" etc, are two-syllable words, different cases of "i/me/my/mine…" ("me-a", "me-us", "me-um", etc)
Check http://en.wiktionary.org/wiki/meus for (more) complete list, btw.

>>2
This could be why whenever I hear an Anglophone (Brit/Yankee/whatever) go and (try to) speak Latin, all I ever hear is butchered language.

          ∧＿∧ fap fap
　fap 　　　（　´Д｀/"lヽ
　　　　　　/´　　　（ ,人）　  ／￣￣￣￣￣￣￣￣￣
　fap 　　（　 ） ﾟ　 ﾟ|　　|　＜ VIVA MEXICO-mexico!!!
　　　　　　＼ ＼__, |　 ⊂llll　＼＿＿＿＿＿＿＿＿＿
　　　　　　　 ＼＿つ　⊂llll
　　　　　　　 （　　ﾉ　　ﾉ
　　　　　　　　|　（__人_） ＼

>>4
Well then go FUCK Mexico, if it makes you so hard!