A few corrections first: Monica NEVER grunted when she hit a drop shot. Then Monica had the Serbian citizenship, she wasn't asked about Croatia. The whole situation was confusing as she was of Hungarian origin, having to play for the Serbs as the part in Yugoslavia she was born was a Serbian area, but waiting for American citizenship, wanting to play as "stateless" (Wimbledon 92) while other players wanted her to play for Croatia.
As for the popularity, she was very popular from 88 to 90 (as Andy mentioned already) but as her career went on so perfectly press and crowds where watching for weak spots and basicaly choose the grunting to pick on - that peaked in Wimbledon 92 when press conferences included nothing but the grunting issue, and everybody was picking on it every day, throughout the fortnight, and eventually it did put her off
Me, I always turned up the volume when she played, to me the grunting emphasised her aggressive play and fighting spirit. It couldn't be loud enough
Especially in 91 Monica was unpopular in the States, they had Capriati then, the "real" American youngster. It became better in 92,93, the crowd usually rooted for her opponent, but hey, they always support the underdog against the no. 1. It was just that she had that reputation of being unpopular.
Joana, have you got some stories about Monica's popularity in Yugoslavia? I know that when she played the US Open final in 91 the streets there were empty cause EVERYBODY was watching it on TV. She was the sportswoman of the year at age 12(!) for the first time in Yugoslavia. They simply adored her.
In her prime Monica didn't spend much time in locker room or at the grounds. She was the first on the practise courts very early in the morning, came back for her match and left after the press conference and interviews which she loved to do and did very professionally - after wins as well as after losses.