Some more info (all cases with @sm1ly's testfile):
**Case 1:** - Open testfile - do first find & replace - ok - do second find & replace - hangs
**Case 2:** - Open testfile - do first find & replace - ok - save changed file to disk - do second find & replace - hangs
**Case 3:** - Open testfile - do first find & replace - ok - save file, close it, re-open it - do second find & replace - **ok**