simplify(ysym(..)) never finishes

[mkruijver]

For specific inputs the simplification never finishes. For example, the following code never finishes running

simplify(ysym("((0.625e-1)*(4*a^2+a^3))/(a^4)"))

while it runs fine with the alternative number formatting below (0.0625 instead of 0.625e-1)

simplify(ysym("(0.0625*(4*a^2+a^3))/(a^4)"))
y: (0.0625*a+0.25)/a^2

Note that the input with 0.625e-1 was obtained from earlier calculations using Ryacas.