The growth in the smartphone market is almost as big as the penetration that music phones are enjoying, but Nokia hasn’t had a chance to get both its feet firmly planted in the former and the company is placing the blame on “software problems.”

No fewer than six handsets have been delayed by these unspecified software issues, including the N91, N71, N80, E60, E61 and E71. The highly anticipated N91 music phone with 4GB hard disk drive should finally be coming ashore sometime this week, with the other two N-series handsets shipping a little later this month. The E-series was targeted for a late March release, so who knows how much longer until these hit the market.

These setbacks, however, have not stopped the phonemaker from pumping out new models: they plan on showcasing the 6136 UMA (Unlicensed Mobile Access) handset at this week’s CTIA Wireless 2006 show in Las Vegas.