Was your software meant for internal or corporate use, or was it meant for the average everyday consumer? Internal use is one thing, but the supposed superstition regards the average end user.
It comes off as if there's no good reason to go for a version 4.9 system, when you might as well wait for them to iron out all the bugs and ship a polished off version 5.
For the end user, this is especially important when you'll have to pay for version 4.9, only to have to pay all over again for version 5. It's like in hindsight you knew you were pissing money away on 4.9 in the first place.
This is exactly what happened with Windows ME and Windows 2000, people just pissed their money away on ME. This is also more or less what happened with MacOS 9, people weren't all too pleased with that either.
Even in my own projects, if I've reached version numbering ending in a 9, that generally means I'm working on lots of internal changes, adding lots of features, and it is likely to have bugs. By the time I'm pretty damn sure most of the bugs are ironed out I'll up the version number and might actually let other people use it.
Edit: If the version numbering is for some background library that end users aren't necessarily going to have to directly interact with or inspect, then it hardly matters, just go ahead and go sequentially.
