help needed- acciaccatura and 32nds

[Stan Sanderson]

Lilypond v2.2.1

I am transcribing a piano piece which, in the upper measure has 
twenty-four 32nd notes ( the piece is in 3/4 time). The bass line is 
six 8th notes.

The piece calls for an acciaccatura of 16th notes preceding the first 
32nd. When the acciaccatura is included, the timing is apparently 
thrown off as indicated by the midi output. The bass line is roughly an 
8th (perhaps three 16ths?) ahead of the treble line. When the 
acciaccatura is removed, all is well.

The run of 32nd notes begins with octavation set on.

I am using bar checks; no errors are reported.

This is the only acciaccatura (so far) which is attached to a 32nd 
note; all of the (many) others appear to be working as expected.

The code fragment is
\acciaccatura { af16[ c ef] } af32^^[( f ef c af ........ 32nd notes 
... ]) |

I tried adding \grace { s16 s s } in the corresponding location in the 
bass line but but it had no effect. I did not find anything in the 
archives.

I would appreciate any suggestions.

Thanks-

Stan