FM hangs on opening certain files

Question

Using FM8.0p277 on Windows XP SP3
I'm currently encountering problems with my installation of FM8.0p277 on Windows XP SP3. These are the symptoms:
When I try to open certain existing FM documents (both structured and unstructed), the Windows hourglass appears, the framemaker.exe process has 50% CPU load (one of two CPU cores), and stays like this for tens of minutes until I kill the process.
I've worked on the same files before without any problems.
No difference if I shut down and restart the PC.
A friend at another company can open the same files using his FM8 installation.
I can however create new documents, save and reopen them. This tells me a fresh installation of FM probably won't be sufficient (but I'll try that later, if necessary).
This is how I guess the problem started: I tried to open an XML file that had been modified outside FM for testing purposes. Either FM did hang or took very long to open the file, anyway, I killed the framemaker.exe process.
What is particularly strange: I quit FM and cleared the temporary folders (both windows\temp and the one in my user profile). Immediately after starting FM again, I looked at the contents of one of the FRM*.tmp files and recognized some text content, which must be either from the XML file on which I killed the application, or from one of my other documents.
The last two observation would indicate there is temporary or cached data in a different place than in the Windows and User temp folders (I've already cleared up both of them while FM was not running).
Do you know where to look? Any other suggestions, maybe?
Thanks a lot in advance,
Johannes

Answer 1

Thanks to anyone who might have considered an answer. Luckily I found the cause and resolved the error. Naturally it was something I didn't think of at first.
(To get even more verbose: FM had been running for a few days already. In the meantime I had copied an obviously corrupted .acf color catalog file into the fminit\color directory, and these color definitions were relevant only to my existing documents. After killing FM because of the XML file that simply took very long to open, it was the first time that color catalog had been in effect.)
Johannes