some funny thing.

[Martok]

^^I've had the message "Your crusade is disbanded as the lands are now back into the hands of the Catholics etc.etc." This doesn't count as a failed crusade does it?

Yes it does (unfortunately).

As Jxrc has already found out, such "Crusade races" always end badly for the human player: If the other faction's Crusade reaches the target province first, then your Crusade automatically fails, with all the consequences (loss of Influence, possible civil war, etc.) that go with it. If *your* Crusade gets there first, however, then you're faced with the unpalatable choice of having to give the province to the 2nd Crusade, or be ex-commed and fight a massive battle.

i thought only orthodox factions got the "hand the province over" message.

I wish! But no, Catholic factions get them too.

[Great Est.]

Concerning Crusades: Currently running an Crusaders XL high campaign and have found more reason to go against my fellow Catholics than any other factions.
I've been turtling the Crusaders, only going after ex-commed Cats after the Pope asks for help and dropping allies that attack fellow cats/are excommed.
Not surprisingly, the Pope asked for help with the Sicilians and Venetians after getting the worst of it in wars against them. I was able to take Sicily, Malta, Naples and Greece in this way. Next up, the excommed Genoese and Spanish, though I have finally begun crusading against the Horde.
I've been at peace with the Egyptians from go (though not allied), as they were much stronger than me when the Pope asked for a Crusade against them. Several Catholic crusades have failed against them.