I'm a proud owner of a Ibanez GIO bass. This instrument for me plays like a dream until winter or anytime of major climate change comes in. I live in Charlotte, North Carolina where the weather is horrible. I'm starting to get really tired of fret buzz on the first frets of my bass and I would love some help to get my bass in its former glory!
I loved my Ibby SR800, but it's neck was really temperamental to weather and string changes. If a minor bridge adjustment doesn't help, you may need a setup as well.
Your problem isn't with the action, but with the relief of the neck which is adjusted by the truss rod. Its completely normal to need adjustments every now and then especially when the weather changes drastically. If its the first few frets then the rod is too tight, slacken off (counter clockwise) a little and you should be good to go.

Hope this helps.