I have a problem with my android device involving specific PDF-files. PDF-files in question: large (40-60 MB) documents with old German frakturscript. The files typically crash after 30 minutes or so; gone are any annotations that I may have made. Flickering occurs infrequently. I know that many android applications such as Lecture Notes do not even recognise old German frakturscript. What do you think might be causing this problem? Will the problem be solved if I purchase a tablet with a better processor? I currently have a device with 1,5-GHz-Dual-Core-Processor with 1 GB RAM. Is that good enough for the purpose of editing large PDF-files?