Just happened across these values while setting up my 10key. 
In the mpxt.cfg they are defined as: 
 
; Redefine Search Keys 
1=1 
2=2 
3=3 
4=f 
5=g 
6=h 
7=7 
8=8 
9=9 
0=0 
 
as you can see 4, 5 and 6 will not search like the rest and need to be reset to the correct values (for a 10 key or of the like): 
 
; Redefine Search Keys 
1=1 
2=2 
3=3 
4=4 
5=5 
6=6 
7=7 
8=8 
9=9 
0=0 
 
Also the values for not loading ID# and preloading has changed a bit in MPXplay. I changed the default values from: 
 
[Play Options] 
Option1Name=Don't load ID3 tags 
Option1Data=-ini 
Option2Name=Preload Songs 
Option2Data=-pre 
 
To: 
 
[Play Options] 
Option1Name=Don't load ID3 tags 
Option1Data=-ihl 
Option2Name=Preload Songs 
Option2Data=-ipl 
 
(I am cheating on the don't load so I only pull the value when the file is highlighted) Note, on faster machines the –ipl is really nice! 
 
Here is the copy from mpxplay defining these values: 
 
ID3-info, file-info: 
 -inl : don't preload (load at skip only) file informations (header,id3tag) (but MXU/EXTM3U works (has effect)) 
 -ihl : load infos of highlighted file only (at cursor move (up/down arrows)) 
 -idl : load infos of displayed files only (displayed in playlist editor window) 
 -ipl : load (all) infos paralell with playing 
 -in  : don't load/display id3tag infos (only filename and time-length) 
 
-saridnour 
			
			
			
				Good point.  A lot of the default config settings haven't been updated in over 3 years.  I'll fix it in the next beta.