Syntax check OK but cannot find .dcu when compiling

[Richard Simpson]

I can run a syntax check OK but when I try to compile, it says it cannot
find certain *.dcu files.

I'm using Delphi 2007 for Win32 on an older computer and a newer one, both
with XP Pro. It works on the older computer. I copied the source code to the
newer computer, keeping the same directory structure. I've repeatedly
checked my project options to make sure that I have the correct directories
listed and the files in the right place on the new computer. If it's
relevant, these are units with no corresponding form file, located in a
separate personal LIB folder.

Both versions have the December 2007 update. The newer computer also has the
April 2008 hotfix. The version info in Help/About is the same, but I can see
that some of the file dates on the two computers are different. For example,
the DCC32.EXE is dated 12-11-07 (3:04) on the older computer (which works)
but is dated 3-27-08 (3:05) on the newer computer (which does not work). The
literature for the April hotfix says that it renamed my existing files to
.BAK, and I found 13 of them. So I manually renamed the real files to .NEW
and removed the .BAK extensions but that did not make any difference. (Of
course, I closed Delphi during this renaming.)

I'm about to uninstall and then reinstall, but (1) it takes so darn long,
and (2) I'm worried that it might mess up my Delphi 6 installation? Any
other ideas before I do that?

Could this be a bug in Delphi if the syntax check is OK but then it can't
compile?