Question: printf in MapleTA 2.5

In order to generate a 2x2-matrix in the question text I use
$display_matrix =maple("printf(MathML:-ExportPresentation(<<($a),($c)>|<($c),($b)>>))");
where $a, $b, $c are random numbers (see below for full question source).

In MapleTA 2.0.1 the question operates correctly. I quote here an exemplatory call to Maple taken from the console:

jvm 1 | To Maple --> printf(MathML:-ExportPresentation(<<(-4),(6^(1/2))>|<(

However, instead of depicting the corresponding matrix, MapleTA 2.5 depicts the Maple code. That this will happen can also clearly be seen in the call to Maple:

jvm 1 | To Maple --> printf("%m", 'Matrix(2,2,{(1, 1) = -2, (1, 2) = 2*2^(1
/2), (2, 1) = 2*2^(1/2), (2, 2) = -4},datatype = anything,storage = rectangular,
order = Fortran_order,shape = [])');

How does it come that MapleTA 2.5 decides to add "%m" to printf? Is there a possibility to fix this by making appropriate changes in a setup file?

I would be grateful for any hint.

Full question source (the question asks for the eigenvalues of the shown matrix):

mode=Multi Formula@
name=eigenvalues (more ergonomic)@
algorithm=$case = range(1,3);
$c = maple("[sqrt(6),sqrt(8),2][$case]");
$sign = range(-1,1,2);
$b = range(-5,5);
$a = $b+($sign)*($case);
$display_matrix = maple("printf(MathML:-ExportPresentation(<<($a),($c)>|<($c),($b)>>))");
question=Bestimmen Sie die Eigenwerte von $display_matrix.
Geben Sie das Ergebnis in der Form eigenwert1;eigenwert2; ... ein.@

Please Wait...