iBooks crashes after upgrading to 8.4.1

Hi,

Since upgrading to iOS 8.4.1 I have observed that iBooks app crashes from time to time. When this happen, iTunes & App Store in Settings does not work. After restarting the system, the problems seems to fade away, but it re-appears after opening iBooks several times. I have obseved this behaviour happens on an iphone6 and on iPad mini (1th generation).

Any suggestions on how to permanently fix the above issue?

Thanks in advance and best regards,

Miguel