Platform: Windows 7, 64-bit version
ISP: Telstra
Type of Internet Connection: Wireless 3G boradband
Internet Connection Speed: Around 3Mbps (but irrelevant in this case)
Date & Time: Since loading game from patch 1.19 at 8pm AEDT 5/10/11
Frequency: Ongoing
Character Name: Thal Icebound
Race: Hyur Midlander Male
World: Figaro
Class/Skill Rank: Thaumaturge Level 46
Physical Level: N/A
Area and Coordinates: Various
Party or Solo: Solo
NPC Name: N/A
Monster Name: N/A
In-Game Time: Ongoing since patch 1.19 implementation
Steps:

I use an international keyboard, which uses keying shortcuts to create characters relevant to various languages. For example, I can type and apostrophe and then and e to make é appear. Or an inverted comma and o for ö. If I wish to type an apostrophe, I have to type a space after so as to instruct my keyboard settings that it's input is to affect nothing, creating an actual apostrophe.

Typing in the chat log, using the apostrophe key results in no initial input, as expected since the keyboard is waiting for my next input before deciding how to process the use of the button. But when I insert the next letter, FFXIV ignores my use of the apostrophe and types only the following character. So what should result in, for example, a ç instead outputs as a c.

I can't instruct it to write a plain apostrophe or quotation mark either - instead I just get a space, as per the second button pressed.

This issue does not persist outside FFXIV, nor was it a problem in version 1.18. If I type the text into a notepad and then copy-paste using Ctrl+V, I can make the international characters appear. I can also do this with apostrophes. This suggests it is not a localisation issue (the international characters are present) but a bug related to keyboard functions.