A couple of strange things with macro workbooks

Well, Hi there!

I was wondering whether you might be able to help me with a few problems I've been having. I'm not a comprehensive Excel user, but am always willing to learn.

I have a macro-enabled workbook (PAYExcel2009, if you want to know). Essentially, the workbook is supposed to be updated every week, and the macros work out tax, print the forms, etc.

When we moved from the old Office 97 systems to the nice and shiney new 2007 ones, the workbooks refused to open. I had neither the time nor inclination to look any further at that point, and simply used the old systems, which were left running for legacy programs (we have a few that refuse to run/transfer at the moment).

Recently, one of the workbooks appears to have corrupted itself (attempting to save results in a "Document not saved" error), I did a little looking around, and tried to find a fix, but nothing was forthcoming. I've written that workbook off as dead, and moved my attentions to the backups, and thought I'd investigate why they weren't playing nice with the new versions at the same time.

I openede up the Master (unchanged) version, and it seemed to work fine with the data, I imported, saved, and it refused to open (gave a network connection interrupted error, with a recovery option, which just dropped all of the macros). I tried simply saving the unchanged version, still unchanged, and it gave the same error (luckily, I made a copy first).

I tried saving the workbook as the new macro-enabled version (.xlsm), and it seemed to keep the macros, but I can't tell, because the trust center refuses to open them (only give the option to "protect from content from unknown sources", rather than open anyway, or trust source, also ignoring the "enable all macros" option I've set in Excel).

I was wondering whether there's a simple reason and, if possible, explanation for this, or whether it's a random bug with this workbook (I suspect there may be quite a few).

Any help is appreciated.