Can I make Subversion + TortoiseSVN case-insensitive for Windows?
Windows does support case sensitivity, but you must send it the correct POSIX flags on CreateFile from the Windows API! A registry key may need changed (SFU/Tools for Unix and Ultimate Windows 7 has this registry entry already set so windows supports case sensitive file names).
Windows is designed off of Unix, but things such as Explorer.exe and other programs are designed to disallow case sensitivity for backwards compatibility and security (mostly when dealing with dos executing notepad.exe vs. NOTEPAD.EXE, where all caps is a virus or malware).
But Vista+ has security attributes which makes this obsolete.
TortiousSVN just doesn't support passing this posix flag while making and renaming files.
Unfortunately, Subversion is case-sensitive. This is due to the fact that files from Subversion can be checked out on both case-sensitive file systems (e.g., *nix) and case-insensitive file systems (e.g., Windows, Mac).
This pre-commit hook script may help you avoid problems when you check in files. If it doesn't solve your problem, my best suggestion is to write a little script to make sure that all extensions are lowercase and run it every time before you check in/check out. It'll be a PITA, but maybe your best bet.