Apple is facing a number of complaints from iPad owners regarding weak wireless signals, dropped connections and slow surfing speeds.

Although users have also reported problems with recharging their iPads from Windows-based PCs or synchronising the tablet with other computers, Wi-Fi issues have garnered the most complaints on the company's support forum.

As of late Monday, the thread titled 'Weak wifi' leads all others with more than 130 messages, and nearly 13,000 views.

"Signal is weak, downloading anything is painfully slow and it will drop the signal and go offline every 5-10 minutes," said a user identified as 'mbell75'. "Pretty annoying."

"It will work fine for a while, but show a low signal. Then, after a few minutes of use, my connection will drop completely and I will have to reset my wi-fi radio," complained 'mlp8104' in another message.

The biggest issue was that the iPad 's Wi-Fi signal indicator would fluctuate, going from full-strength to the lowest level without warning, or any change in the tablet's location.

"My wifi went down to 1 bar after working great for a few hours," said 'syunker'. "My download speeds started to crawl, I couldn't even surf the web. I rebooted my router and it didn't help."

Several users said their iPads could not acquire a signal, or only a faint signal, while other devices, including new Apple laptops and iPhones, had no similar trouble.

"In our living room where laptops get a full signal, my iPad gets a very poor signal which is so bad that it even cuts completely out sometimes," complained 'Panjandrum'.

"I had to walk the iPad into the same room as my router to get a movie rental to download."

As is often the case on Apple's support threads, users hoped that a software update to the iPad's operating system would not only solve their problems, but be released soon.

Others, however, chimed in to say that they were perfectly happy with their iPads' Wi-Fi signal, which was strong and stable at home, work and in public hotspots at locations such as Starbucks.

Some who reported that their iPads intermittently lost a Wi-Fi connection said that they solved the problem temporarily by shutting down the iPad, then restarting it.

"But should I have to do that with a device that costs this much and has so much hype about changing the way we use the Net?" asked 'sandersn' in a different thread.

Apple posted several iPad-specific support documents to its website, including one that suggested users modify settings on their wireless routers.

Another troubleshooting document told users to "move closer to the Wi-Fi router or hotspot", if they were having problems.

Suggestions from users ranged from disabling the iPad's 'Ask to Join Networks' feature to rebooting routers.

The version of the iPad on sale in the US now connects to the internet only via Wi-Fi; a more expensive model that also uses a 3G connection is not slated to ship in the US until later this month. The UK won't get the device until the end of April.

Over the weekend, users voiced frustration at other problems, including an apparent inability to recharge the iPad through USB ports on many computers, keyboards and hubs.

Consumer Reports said that its initial testing indicated that the iPad would recharge via the USB ports on desktop and laptop Macs, but failed to do so on USB ports in a variety of Windows PCs, or through the ports on a keyboard directly connected to a Mac.

PC Advisor's sister title Computerworld revealed it noticed the same 'Not Charging' message when an iPad was connected to the USB port on a wired Mac keyboard.

Apple clarified the recharging process in a support document published Sunday, noting that the iPad requires a high-power USB 2.0 port to charge while it is in use.

The iPad will only charge via older USB ports, including those on most Windows machines, when the tablet is asleep, Apple said.

See also: Apple iPad sales exceed 300,000 on day one