what's fishy to me: it shouldn't make a difference
whether you use formic acid or acetic acid. after
all you're just neutralising an Na-Salt.
did you get the Na-Salt? did you wheigh it?
did you use anhydrous EtOH, freshly cut Na, and
did you reflux your EtAc over P2O5?
i've heard that this reaction works rather well if
anhydrous conditions are used. of course nowadays
you use a mag-stirrer...
![Tongue :P](https://thevespiary.org/talk/Smileys/default/tongue.gif)