Try out the free trial version of PlanMaker Mobile (you can use it for 30 days with full functionalities), that's by far the best spreadsheet app for Android.
All other office apps for Android (QuickOffice, Kingsoft Office, Polaris Office, Office Suite Pro, ThinkFree Office, Olive Office, Documents To Go Pro - I tested them all!!) have plenty of oddities with several Excel files (you've seen one of them, others would be e.g. problems opening password-protected files, or new xlsx format; files that can be opened have formatting losses, missing charts, messed up tables, and such more...).
The interoperability of PlanMaker Mobile in contrast to those is outstanding, I don't have any problems going back and forth faithfullly.
Btw., PlanMaker Mobile gives you over 330 built-in functions (more than any other), and is is the only spreadsheet on the market that allows exporting sheets directly to HTML, that masters syntax highlighting, and rotating text, that shows formula instead of results, shows and updates 3D charts, can generate PDF files directly from within the application, allows conversion from one format into another, lets you embed any TrueType or OpenType font, plus a lot more. No other spreadsheet is so feature-packed. Anyway, I'm very satisfied with it.