Internal Data Error

:frown;
I manage quite a large intranet site and recently upgraded to MX2004. I was
running a find and replace sitewide to locate a phone number that needed
updating. When I double clicked on a result from the list, make the change and
then try to save it I got "An FTP error occured - cannot put default.htm.
Dreamweaver encoutered an internal data error. Please try the opertation
again". This is not the first time this has occured so I decided to raise it
here. I did find before that if I quit, relaunched and tried again it would
work. But this is not the kind of thing you want to do with a list of 100 phone
numbers to change and it takes 10minutes to scan the site on each find
operation. 10 minutes x 100 = :|.

Any ideas to improve this? Anyone else had this problem?