Version:           4.7 (using KDE 4.7.2) 
OS:                Linux

Trying to import filter rules from old kmailrc (from KDE of kubuntu 10.04) results in wrong destination folders (-> "Unknown folder"). In consequence, none of the imported filters is not saved when quitting the dialog (maybe due to the above error?). Fixing folders manually seems to work but if only one folder is forgotten, none is imported :-(

The only significant difference I found between old fashioned filter rule and actual one is that folders have been referenced by filename while now they seem to be referenced by a number. A diff looks like this
diff -y new old
action-args-0=160  |  action-args-0=.Office-Libre.directory/documentation

Is there any workaround or do I have to manually adjust all my 300+ filter rules? (As written above, I've already tried to fix a couple but the whole bunch did not get saved - maybe due to the still incorrect ones?)

Reproducible: Always

Steps to Reproduce:
Open filter dialog, import old kmailrc with written folder names in field action-args-x. 

Actual Results:  
Folder destination says "Unknown folder ..." (or similar, I'm working with German version saying "Unbekannter Ordner ...")

Then:
1. leave the dialog and reopen it without correcting folder destination: imported filters are lost completely.
2. correct some of the filters but not all, leave the dialog and reopen it: again none of the filters get saved.
3. correcting all filters seems to work (I did not try all of my 300 filters but only 10-20)

Expected Results:  
At least all manually corrected filters should stay saved.

Better: Adjustment of destination folders should happen automatically (e.g. by matching folder names with old file names and converting file names to numbers automatically if matching 100% resp. asking the user if matching is incomplete)

OS: Linux (i686) release 3.1.0-1.2-default
Compiler: gcc