It has nothing to do with "older" or "Newer". Typically the PDA's are not reset for days, weeks, or months at a time. If you've ever tried to keep your PC on for this long, you would notice the same thing happening. Typically the hard reset I described fixes these "issues" and I get myself a working PDA. Regardless: You do not hide PDA's. Best Practice dictates that all PDA's must be kept in TSC and turned in likewise once their use is completed, and IF YOU DO truly absolutely "need" a PDA for your job (planogram set, for example), then just tell management you need one and wait. It's win/win, as you get to sit and collect money in the meanwhile.
But never, ever, EVER, hide a PDA. It WILL get you in trouble.