TortoiseDiff to diff source code but it seems to have become an image diff'ing tool?

I just downloaded and installed the newest Tortoise 64 bit on Win 7, and then start up TortoiseDiff from

START -> All Programs -> TortoiseSVN -> TortoiseDiff

It used to be able to diff two source code file, but now it seems like it is an image diff'ing tool. Anybody knows how to get the tool to diff source code files?

Update:

If the two source files are in different folder, seems like the TortoiseSVN context menu by right click won't show the "Diff" option. After copying the other file to the same folder, if both files are highlighted, then there is a "Diff" option, and TortoiseMerge is the program that comes out to diff the file. So how to use Tortois开发者_如何学运维eDiff from the START menu to diff 2 files? It seems like it is for merging file if it is invoked from the START menu.

The program menu should have two different entries:

TortoiseMerge and TortoiseIDiff

(note the 'I' before 'Diff')

Just start whatever you want (TortoiseMerge for diffing text files, TortoisIDiff for diffing 'I'mage files).