Ok. I've performed some tests with GUI.
1. c:\temp\22;c:\temp\33 - files are found
2. "c:\temp\22";"c:\temp\33" - files are found
3. "c:\temp\22;c:\temp\33" - files are NOT found
And now the issue is reproducible in pure GUI mode without UDC.
1. Open Find files dialog
2. Enter some findable mask (files must be found for issue to happen)
3. Enter some path
4. Press start.
5. After files are found close the RES tab
6. Close Find files dialog
7. Now change path
Well, maybe not 100%, but almost each time