ICM says this is a fold. I always thought this was a push...wtf

[Unoriginalname]

NL Texas Hold'em $20 Buy-in + $2 Entry Fee Trny:14334452 Level:5 Blinds(75/150) - Thursday, July 28, 15:55:54 EDT 2005
Table Table 13810 (Real Money)
Seat 4 is the button
Total number of players : 5
Seat 4: pkrplyerAA ( $1470 )
Seat 5: shannonsoss ( $1545 )
Seat 7: RAF77 ( $3290 )
Seat 8: Hero ( $880 )
Seat 10: lacvanle ( $815 )
Trny:14334452 Level:5
Blinds(75/150)
** Dealing down cards **
Dealt to Hero [ Ad 7c ]
>You have options at Table 13973 Table!.
Hero is all-In [880]

I don't get this at all. A7o is a pretty decent push hand. I don't think I'm going to get much better at this point. I'm short stacked and starting to get desperate and those 225 chips will increase my stack by about 25%. I post the BB next round, which will make me even shorter. Why is SNG power tools telling me that this is a bad push unless my opponents will only call with the top 8% of hands? That's pretty damn tight. Am I going crazy? Is this really an easy fold?