My auto switching works fine i dont know what the hell your doing wrong with it its one of the main reasons i use UnleashX...
I can tell you though that the US version of GTA 3 and VC isnt signed so UnleashX doesnt know if its a PAL game or NTSC (press start on the title and go to information it will tell you the region it thinks it is which for those 2 will be 0) thus keeps it booted in mode your currently in to change this you have to go into the items list (items.xml) and manually input a region which is what somebody has said already in this topic.
this is what your looking for:
<Item TStamp="
??" Action="F:\Games\Grand Theft Auto Vice City\default.xbe" Region="0" Icon="E:\UDATA\
??\TitleImage.xbx" ID="
??" Preview="F:\Games\Grand Theft Auto Vice City\preview.wmv">Grand Theft Auto: Vice City</Item>
Change Region="0" to Region="1" and Unleash will boot it up in NTSC everytime you can also check to see if other games also are set to 0 also incase your worried this wont effect your eeprom in the slightest since it doesnt write to it i assume it just changes it "on the fly".
If this doesnt work for you might aswell quit the chances are your not going to get it to work and there isnt anything it could be apart from that (sorry to be blunt)
Also i wouldnt use Force PAL 60hz since i find it breaks a few games which work normally but do enable PAL 60.