Creating PDFs

Up until about 3 weeks ago I used to be able to create PDFs using this product with file names that included Russian Cyrillic characters. Suddenly PDF Creator stopped accepting the Cyrillic characters and now if I put any in the file name the creation process just stops as though it never started. There is nothing in the print queue so it hasn't stalled it just disappears. If I then save the file witrh just Latin characters it goes through perfectly.

I haven't changed any settings in PDF Creator etc.

I know a work around is to save the file in Latin characters and then using Windows Explorer rename the file but that is getting to be a pain.

My OS is XP Pro SP3

Any ideas anyone ??