MYOB customers are up in arms after the company released faulty software and failed to cope with a barrage of calls from tax agents who claim they are unable to do business.

Two weeks ago, the ASX-listed software supplier put the latest release of MYOB Tax 2001 online for 4,000 customers, mainly tax agents and accountants, to download. The release incorporated legislative changes from the Australian Taxation Office and was therefore a mandatory upgrade for tax accountants wishing to file tax returns.

Many customers had difficulty downloading the software and then had trouble running the product. MYOB responded by issuing all 4,000 customers with a new version of the software last week, this time on CD-ROM.

However on Friday, customers who contacted The Australian Financial Review said they had been unable to run the new software. "MYOB sent me a licence activation file by email [to activate the CD-ROM program] and when I loaded it, the system crashed," said one public accountant from Melbourne who declined to be named.

"Without this software we cannot work. It's our livelihood." MYOB acknowledged there had been difficulties with the July 1 releases, including "undocumented features", otherwise known as bugs. However, the company's national marketing manager, Mr Andrew Fiori-Dey, said the situation was under control with the new release of the software.

Mr Fiori-Dey said the company had expected to receive more calls after the software was released and had put on 26 extra people to ensure its call centre could cope with the increased traffic. "We recognise the role we play for accountants. We know they are in their peak season and we want to help them to be profitable and efficient," Mr Fiori-Dey said.

But on Friday, customers seeking help via the hotline were advised by a recorded message that the company could not take calls. Customers were advised to call back later. "This is the most critical piece of software we use.

When it doesn't work, we can't do tax returns which are our bread and butter. Right now we are stuck, thanks to MYOB," said one Sydney customer who also declined to be named. MYOB said many of the download problems were caused by customers who failed to observe the hardware specifications recommended by MYOB.

It also said its developers had worked "around the clock" to incorporate the legislation changes which were released by the ATO late last month. MYOB said it was "constantly addressing software bugs" and would release a series of patches and CDs in coming weeks.

MYOB customers have pointed out that suppliers of competing tax software had managed to incorporate the changes into a usable product by July 1.